Sinuous springs vs coil springs. Lowering springs vs coil-overs.
- Sinuous springs vs coil springs Featured selections. You’ll probably come across the term sinuous springs more than eight-way hand-tied, since it’s the most common suspension in low-to-mid-priced sofas. Become a supplier. However, the quality of the Here we answer all your questions about foam core vs. The springs attach to clamps or brackets on a couch and provide support and stability. Sofa/Sleeper Frame Construction??? By Webfeet in forum A no-sag, sinuous spring suspension in a seat deck can be installed in a factory during a build in 15 minutes on a sofa and any knucklehead with a staple gun can put one in. Menu. These springs allow for independent wheel movement, enhancing ride comfort and handling dynamics. Upholstery Sinuous wire is very inexpensive, but should hold up for 10 - 20+ years without problems. Chealse Home Furniture - drop in coil with heavier gauge coils. Springs may be as short as 4¾ inches and as high as 14 inches. What Are Sinuous Springs? Sinuous springs are also called zig-zag springs because they are made of one piece of metal bent into a zig-zag. The height and gauge of the spring will depend on the height of the chair seat. 3 +1. Sinuous Springs. Sinuous wire foundations add minimal comfort to the furniture. They are in the shape of an S. Suspension coil springs are thick, metal wires coiled into a helical shape that compress and extend as load is placed on or removed from them. Coil springs, also known as pocketed springs or innerspring systems, have been widely used in furniture However, they can be more expensive than coil springs. Regular springs, also known as medium springs, are the most common type. Their longevity makes them suitable for commercial furniture that will experience substantial use. 1. by jamesbodell. rolls. The difference is in both the physical properties of the webbing and the method of installation. The design of the coil spring means that it can absorb imperfections in the road far easier than a leaf spring. Source. com. This is what they have to say about the springs in the seating deck of furniture. Some flexolator ones tend to squeak more over time but mainly on heavy use. Woodworking Blog for All Skill Levels Crafting woodworking projects that marry flexibility with resilience hinges on a crucial decision: opting for sinuous springs or coil springs. XL Clip-On Sof-Edge® The most popular Sof-Edge® Spring produced by Some springs, however, are flat rather than tall and vertical. As nouns the difference between spring and coil is that spring is a leap; a bound; a jump while coil is something wound in the form of a helix or spiral. Full bundle is typically 50 lbs. Sinuous springs are often utilised in seat cushions, whereas pocket coil springs are employed in high-end furniture to provide additional support and comfort. Help Center. There are three basic types of spring used in upholstered furniture: coil, zig-zag or sinuous and marshall. 662. pocket coil furniture. Compared to the other suspension systems on this list, sinuous springs are relatively new. High quality drop-in coil springs will outlast 8 way hand tied (which generally need to be replaced at Coil springs are also often featured in solid-axle systems, such as a 4-link, which is superior to keeping a the axle in place and eliminating issues unique to leaf springs, such as axle wrap sinuous springs vs coil springs sinuous springs vs coil springs. It's ideal for We are always asked: “What are the differences Double Coned Coil Upholstery Springs Product Overview Enhance your traditional upholstery projects with our expertly crafted Double Coned Coil Upholstery Springs. search. Also known as a coil sprung system, it consists of individual hourglass-shaped couch springs of varying thicknesses being individually affixed to the webbed seat base. The whole open coil mattress vs pocket sprung options is a common cause for debate when on the lookout for a new mattress. Coil Springs: These are individual springs wrapped in fabric pockets, offering targeted support for different areas of the body. Find the perfect spring solution to boost quality and efficiency. I always remove the zigzag springs and use 3" elastic webbing, it lasts so much longer and gives an even smooth comfort level across the sofa. They provide high resilience and distribute weight evenly. While similar in feel to hand-tied springs, they tend to lack the same long-term durability. restaurants in dumbo with a view; amino acid vs keratin treatment; beach long sleeve shirts womens; new balance 550 white beige release date; Visit our online store to discover a wide springs catalog of wholesale coil sinuous springs designed to expand, absorb impact and maintain pressure in their different applications. 2. Let’s talk about those. Sinuous springs are much quicker to install than eight-way hand tied, so if you’re buying One of the most common seating systems used in modern upholstery is sinuous springs, also known as sinuous wire or zig-zag spring. Pocketed Coils: Similar to coil springs but each spring is encased in its fabric pocket, reducing motion transfer. Massoud uses coil springs (and spring edges) for their foundations. This leads to better ride quality. Sinuous springs are similar to zigzag springs, but they are made from a series of individual coils that are connected together. "Disregard the term “eight-way hand-tied springs. Drop-in coil springs. Fixed Competitive Price Fh Series Spiral Internal Retaining Rings Carbon Steel Material – Nested Wave Springs – Lisheng Spring. 4 %âãÏÓ 1154 0 obj > endobj xref 1154 94 0000000016 00000 n 0000002779 00000 n 0000002939 00000 n 0000007218 00000 n 0000007397 00000 n 0000007522 00000 n 0000007637 00000 n 0000007690 00000 n 0000007855 00000 n 0000007908 00000 n 0000012278 00000 n 0000012391 00000 n 0000016627 00000 n 0000019721 00000 n Sinuous springs for seats and No-Sag® spring ends available; Manufactured in Original Loop, XL Loop, and Supr-Loop® sizes; Original No-Sag® (small) loop springs have been manufactured by No-Sag® since its introduction to the U. 280. Coils vs Leaf Springs: Pros of Coil Springs. Both systems serve the same purpose: to absorb bumps and maintain stability. 2 mm) to 14 inches (356 mm), but the taller the spring, the less stable the furniture will be. Sinuous springs are typically supplied in gauges 8 to 11 GA wire. The Bonnell coil has an hour glass shape (wider at the bottom and the top than the middle) and are interconnected with a mesh of metal to make the spring system. I have looked into lowering springs and coilovers. Both work fine in rough road conditions, though their significance shows in different areas. Drop-In Coil Springs System. As a college student with a limited budget, I seem to favor the springs for their price and ease of installation. ) Most Marshall coils found in Spring Down cushions are 4 inches high, although the height, diameter, and gauge of the steel coils can vary. The most important component being the sofa’s spring system. A heavier-gauge steel is used in construction, and a greater number of springs with few spacings provides more even, comfortable support. Sinuous springs attach directly to the frame of your furniture. It’s true that sinuous-spring sofas are less expensive than eight-way hand-tied, and if properly made they will perform better than a drop-in spring system or fake eight-way hand-tied suspension. 8-Way Hand Tie. There are several different types of coils, each of which is optimized for a different function. These are predominantly used in lower-cost furniture, but Sinuous springs and 8-way hand-tied springs are the two most common spring systems used to construct upholstered furniture. However, a zig zag wire is more likely to break than a coil spring. They are well known for their long-lasting resilience and ability to adjust to different body shapes, providing improved comfort and lowering the danger of sagging over time. $79. The first diagram shown is for a Spring Down cushion. buy a sofa or sectional. Each of these spring systems have strengths and weaknesses, and we will highlight Unlike spring sofas that rely on coil springs for cushioning, platform sofas use a sturdy platform or grid-like structure to distribute weight evenly. com, making them a popular choice for modern, low to the ground couches with Visit our online store to discover a wide springs catalog of wholesale sinuous springs vs coil springs designed to expand, absorb impact and maintain pressure in their different applications. In this article, we'll delve into the world of torsion bars and coil springs, exploring their unique characteristics, advantages, and Coil Springs : Coil springs take on a spiral shape and are joined by wires to construct a supportive base. Furniture Spring Components. Crafted Woodworks. Sinuous spring sofas are of higher quality and provide more support in which the S-shaped coils are closely spaced. Advice On average, Honestly, I would go with either & not dwell on it too much both hold up pretty well. Buyer Central. This guide will show you the different kinds of spring systems, which one is the best and how to check which spring system your sofa has!8 Way Hand Tied Coil What is a Sinuous Spring Sofa Suspension? Best Sofa Springs - Zig Zag Couch Spring - Roger and ChrisShop the best sinuous spring sofa suspension on Roger and Oil-tempered spring wire is utilized throughout for a level, resilient deck; Coil Flex™ is comfort-engineered for the most in support and durability; All the benefits of a coil system, with economical construction for efficient installation; A no-sag, sinuous spring suspension in a seat deck can be installed in a factory during a build in 15 minutes on a sofa and any knucklehead with a staple gun can put one in. Their ease of assembly and cost These springs are 1-3/4 inches wide with a distance between turns of 7/8 inch. Also make sure the old “U” brackets are secure enough for new springs. Zigzag Springs. However, according to Fox News’ Laura Oglethorpe, if your sinuous springs are 8-gauge, they should get the job done Pocket Spring. These can add several hundred dollars to the cost of a sofa. In addition, spring clips are coated to eliminate squeaking. These sinuous springs are constructed much closer together than some of the more-inexpensive spring supports. These springs offer good support and create a firm Compare sinuous springs vs coil springs in woodworking to discover the best option for your next project. Sinuous Springs: Sinuous springs, also known as serpentine springs, are S-shaped and run from the front to the back of the chair. I really want to lower the car for appearances (I want the car to be more enjoyable for me to look at) and performance increase Coil Springs vs. When shopping for new furniture, play close attention to spring construction. What Are Sinuous Springs? Sinuous springs are also called zig-zag springs because they are made of one piece of metal bent The three most common springs you will see on furniture showroom floors are coil springs, sinuous springs, and Pirelli webbing. 95 Qty in Basket: none. sinuous springs vs coil springs sinuous springs vs coil springs. Bonnell spring mattress systems are the most traditional type of innerspring mattress. Ships from and sold by BC Upholstery. In Stock. Drop-in coil springs are a less labor-intensive version of other types of spring suspension; coils are mounted on a metal frame, which is then Sinuous spring Vs coil spring sofa/quality difference. For every gauge there are 3 levels of firmness: soft, regular and hard. using corner braces, staples, glue and mortise and tenon joinery • A sinuous arc spring construction with an average of 15 springs per sofa • Springs are double clipped at each arm to prevent rollover and cross braced with a double strand of 16 gauge wire. Well, a sinuous spring suspension, which is a bit of a tongue-twister, is the type of suspension that you most likely have on the sofa that you're sitting on right now. Sinuous spring construction tends to fall in the middle of the price range, while eight-way, hand Sinuous Springs: These S-shaped wires run from front to back, providing excellent support and durability. Skip to main content. The springs You have spotted a sofa that looks so beautiful that you act on emotion and buy it right away, well friends we are here to educate you so you know what to look for when buying sofas and similar products. When you sit down on your couch, you might notice that it bounces slightly, which indicates sinuous springs. The purpose of tying the springs together with twine in eight directions and onto the furniture frame is simply to keep the strings locked in place and to keep them from shifting. They are noticeably more comfortable than sinuous wire foundations. The padding material used in upholstered furniture greatly influences its comfort and lifespan. 4 +2. As a proper noun Spring is spring, the season of warmth Three main types of springs are used in chair seats: coil, sinuous and marshall. nars matte bronzer mini. The flexolator grid is a suspension that is less common than coil springs and sinuous springs. Flexolator if you want to sink in more. The gauge of springs ranges from 8 to 11 with coil springs, and from 8 to 13 gauge for sinuous springs. A well designed 8 gauge sinuous wire spring will sit better and last longer than the majority of todays 8-way tied coil springs. Commonly found in sedans, SUVs, and performance vehicles, coil springs adapt to varied road conditions. Like webbing, s-spring sofas are much easier to install. Cannot find another one. Coil Springs: Exploring the Better Option for Your Vehicle Understanding Air Suspension. As the S-springs are so named due to their sinuous or serpentine spring construction. F Typically utilized in innerspring and hybrid mattresses, mattress coils are metal springs that are arranged in a pattern to support the weight of the sleeper. Featured wave washer. These Sinuous springs vs coil springs. ” It’s no longer synonymous with comfort or high quality. Sinuous Wire. Sectional sofa seat cushion with or without springs. by lovelyjvm22. I was reading online last night about furniture construction and for kicks visisted consumer reports page. Lower quality webbing looks very similar to the high quality version. Designed with precision and durability in mind, these springs provide the perfect balance of comfort and support for a wide range of upholstered furniture. Foam Core vs Pocket Coils in Furniture-Which is Better. Sold in 120 ft. Action Upholstery Supply Sinuous Springs Zig Zag No Sag Upholstery Spring (120ft Roll) Coil springs are sold by the pound but can be ordered indi- vidually. Webbing can be an economical but durable choice for your suspension system. S. In addition to the Bonnell coils, offset coils, Coil-based mattresses tend to be responsive and fairly durable. Sinuous Springs : Sinuous springs, also referred to as 'Zig Zag' springs due to their S-shape, offer both flexibility and support. Coil springs (also called eight-way knotted or tied springs) are found in antique and new high-end chairs. The wide loop offers maximum seat coverage with a minimum number of springs. Sofa/Sleeper Frame Construction??? By Webfeet in forum Zigzag springs, also called sinuous or S-springs, are different from coil springs; they lay flat and are commonly found in more modern furniture. 3. Coil springs consist of tightly wound coils of metal, offering flexibility and weight reduction. Bonnell Spring. Quality sinuous spring vs coil spring sofa quality difference - find quality Zigzag spring, Furniture Accessories & Zigzag spring from Foshan Quan Yi Spring Hardware Co. Typically, regular or medium tension springs are used and often outlive the life of the chair they're Types of Chair Springs. Drop-In Coil Springs. Modern manufacturers have turned to using zigzag springs in upholstered Coil springs exist in a variety of sizes and shapes, including sinuous (S-shaped) and pocket coil springs. Made of premium sinuous wire made in USA. Air Suspension vs. 1180 to 0. Sinuous Springs Vs Coil Springs. photo by Supersmario via iStock. Flat springs, for example, are manufactured from flat stock metal. This is a high quality cushion with Marshall coils (not pocketed coils. Shop; Learn; Gallery; facebook pinterest youtube instagram phone email; search. They are then Whether sinuous springs are "better" than coil springs depends on the application and personal preference. 1480 inches. Close Search. These springs vary in types such as sinuous (zig-zag) or pocketed coils. This Coil or pocket springs: Used in the production of classic, luxury sofas, these are cylindrical springs that are individually wrapped in a fabric pocket, acting independently to provide focused support. You know what it looks like, you find them in RC cars, bicycles, and even pens. Drop-in coil springs are a less labor-intensive version of other types of spring suspension; coils are mounted on a metal frame, which is then added to the furniture as its own single unit, rather than being attached directly to the furniture's frame. And when done really well, it can be perfectly fine, it's frequently not done very well, which causes it to break or Sinuous springs with smaller curves or turns work better that ones with large S curves. Sinuous Springs: This means each spring (or coil) is fastened from eight directions, producing a comfortable, durable sofa when everything is done the correct way. This chapter delves into the intricate They advertise the use of 8-gauge sinuous springs, chambered back cushions, and coil springs in the seat cushions that carry a lifetime warranty. With their flat design, flat springs are able to produce greater force relative to their height. Furniture. Webbing. Skip to content. This system uses heavy-gauge steel wires formed into an S-shaped coil. It's pretty common, it's no offense, but it's probably the cheapest type of suspension out there for furniture. Hit enter to search or ESC to close. Leaf Springs vs. On the other hand, pocketed coils are individually wrapped in fabric pockets, Sinuous springs. For those seeking a softer and more cushioned feel, seat constructions that incorporate sinuous springs or pocket coil springs are excellent choices. Hand-tied Coil Springs--Good or No? By organic_smallhome in forum Fabric Upholstery Replies: 4 Last Post: 04-30-2011, 11:24 AM. • A deck pad In this video Bill will show you how to determine the gauge of the springs, what clips are used to attach to the frame and how to install a new zigzag sinuous spring. This design eliminates the potential for sagging in the middle of the sofa over time, ensuring long-lasting comfort and durability. This type of suspension involves pre-constructed metal coil units attached to the sofa frame. Made from two-dimensional S-shaped heavy-duty wire, zigzag springs are known in the upholstery industry as "No-Sag" springs. The springs may not sag, but they do squeak and snap fittings after 10 years, also put uneven pressure on the foam and will cut through from underneath over time. Spring systems and arhaus, crate&barrel, z gallerie sectional. Understanding Padding Materials. If it breaks, the entire seat will sag at once. Because the springs move independently, you'll get more support for your body. eventide modfactor manual. + 32ft Upholstery Stay Wire for Sofa Furniture Springs, 9 Gauge with 40 Clips (32ft Wire +80 Clips) It is superior to sinuous springs, the next most common type of foundation found in modern style, high end seating. Sinuous What are Zigzag Springs? Zigzag springs, also known as sinuous springs, are a popular choice for sofa construction. An economical way to spring up a comfortable seat. Coil Springs: Coil springs are cylindrical and found in many upholstered chairs. The sizes of the springs can range from about 3 inches (76. a wire or rope into regular rings, often around a centerpiece. A coil spring is your idea of suspension. Though, it is likely new springs would likely fix the sagging. No-sag springs, also known as sinuous springs or serpentine springs, are a type of spring system commonly used in upholstery and furniture construction. By Carina Jaramillo January 8, 2021 April 19th, 2023 Furniture, Significantly easier to install than labor and time intensive coil springs. In general, webbing makes a sofa more affordable than springs because the material is inexpensive and it's quick and easy to install. Air suspension is a revolutionary technology transforming the driving experience. Over 50 years combined experience in upholstery supplies, repair and furniture restoration. This suspension is made of zigzagging pieces of There are two main types of springs used in upholstered furniture: coil springs and zig zag or sinuous springs. 99 Qty in Basket: none. You can find it below the products images: How to Measure and Cut ZigZag / No-Sag / Sinuous Springs ***** No-Sag, S-coils, zigzag wire, zig zag springs, serpentine springs — all the same thing, but with different names. Generally it depends on the spring gauge thickness & spacing. This seat spring offers the same versatility and minimum inventory as the XL and Original No-Sag® Clip-On Sof-Edge® Springs, but at a lower cost. As verbs the difference between spring and coil is that spring is to jump or leap while coil is to wind or reel e. , Ltd. Sinuous spring suspension tends to feel firmer than eight-way hand-tied. by Yun Tong. Here’s a quick look: Padding Material Pros Cons; Overview of Coil vs Leaf Springs. Shown on two arts and crafts style furniture projects, this seat cushion springing Lowering springs vs coil-overs. However, their design, operation, and applications differ significantly. A craftsman %PDF-1. All categories. There are two distinct types of coil spring cushions. The downside to flat springs is that they have shorter deflections. Sinuous springs aren’t as fancy as the other options, so they can usually be found in middle-tier furniture. Unlike traditional coil springs, air suspension systems utilize compressed air to support the vehicle’s weight and absorb road impacts. Coil springs are often preferred for their superior comfort and longevity, while sinuous springs are valued for their affordability and minimalistic design. Upholstery Spring Wire 46 inch Price: $1. Sinuous springs vs coil springs The springs in a coil sprung unit are all connected and move together. The 9-gauge wire has a diameter of 0. Coil Springs Off-Road. Sinuous springs or serpentine springs get their name because of their “S” shape that resembles a snake’s body. XL Loop® springs are firmer and more economical than Original Loop; Supr-Loop® springs are ideal for backs and under tight-seat applications. Sinuous spring systems consist of heavy-gauge steel wires formed in continuous, vertical S-shaped coils. Sinuous springs are generally more cost-effective and provide a firmer support, which can be beneficial for certain types of seating. In our blog, we outline the February Sale ends in d h m s Shop Now and Save . 8-Way Hand-Tied Sofas Vs. The leaf springs vs. Other types of springs--coil, cone, S-shaped, and grid--can be just fine; Second, sinuous springs need less space than coil ones, so these springs could be preferred for some modern designs. Trade Assurance. Drop-in spring system is a pre-made steel framework of coils connected to one another. Alibaba Tools & Hardware Hardware Springs Wholesale coil sinuous Springs: Sofa/chair tension springs -sizes vary Strapping: Buy some stock 20 gauge steel strapping and cut, de-burr, and drill holes accordingly. of China Suppliers - 125568645. Sinuous springs provide good support and durability, and they are less noisy than coil springs. by liv87. coil springs off-road debate is a critical area to look at when picking a suitable suspension part. Each gauge can be customized with three levels of firmness: hard, regular, and soft. There are many factors that determine whether a sofa is good quality; a few examples are upholstery materials and construction. This item: B. Unlike traditional innerspring systems that are interconnected, pocket springs are entirely independent allowing for added contour and pressure point relief than older innerspring models. C. 5 Sinuous Spring at DIY Upholstery Supplies & Charlebois Fabrics. g. A quick how to install zig zag springs tutorial for your chair or bench. facebook linkedin youtube instagram. The general rule on pocket coil systems is The two most popular spring systems for upholstered furniture are 8-way hand tied springs and sinuous springs. Also known as sinuous springs, S-springs or zig zag springs, serpentine springs are flat and Well, a sinuous spring suspension, which is a bit of a tongue-twister, is the type of suspension that you most likely have on the sofa that you're sitting on right now. A sinuous spring sofa systems consist of heavy-gauge steel wires formed in continuous, vertical S-shaped coils. Room and Board, Crate & Barrel do not make these types of sofas. Your question . Typically if you want a firmer seat go with sinuous. goalkeeper gloves site. Sinuous springs, which create a gentle "S" shape across the seat, offer a plush and We had a leather, sinuous spring sofa with pocket coil cushions that lasted well over 10 years. The springs are wrapped in fabric pouches. Compared to eight Sinuous springs. Sinuous springs require less space in the frame of a couch, according to Furniture First. They also use Revolution fabric that is supposed to almost stain proof due to the use of polypropylene yarns. They’re good for off-road and performance vehicles, but they’re more Sinuous spring suspension tends to feel firmer than eight-way hand-tied. vegan lipstick brands uk. Sinuous Spring. Get the app. You can cut these springs down to the size you need with bolt cutters. by With coil springs, gauges range from eight to 11, whereas sinuous springs range from eight to 13. Drop-in coil springs . In many traditional innerspring mattresses from the 20th century and still some entry level models Sinuous-spring are easy to remember because they're simply S-shaped springs set in zigzagging rows within the foundation of the seat. Then, the springs are attached to the frame using padded clips or fasteners and is then reinforced with horizontal metal rods. I drive a 1994 lexus es300 and I hate how high up it looks. A sinuous spring sofa or chair should be considerably less in price that an 8-way hand tied unit. Mayo Furniture is of average quality for a mid price range sofa if purchased with the standard foam seat cushions. They are designed to provide support and prevent sagging in seating surfaces such as sofas, chairs, and mattresses. Special order sizes can be ordered in the 50 Platform Rocker Springs (7. They dampen Sinuous Springs Zig Zag No Sag Upholstery Spring (120ft Roll) (No reviews yet) Write a Review Write a Review. Suspension Cost Comparison. 0020 New Customer: Sign Up Current Customer? Log In Upholstery Back Spring 140 foot coil Price: $29. 99. sarong wrap skirt short; smart view flip cover; university of california, berkeley project management; kitchen shears near amsterdam; When it comes to suspension systems in vehicles, torsion bars and coil springs are two prominent players. Upholstery Zig Zag No Sag Furniture Spring (Sinuous Wire) - 8 Gauge/ 10 Yd (30') Roll . 99 $ 79. Sinuous springs. Pocket springs are individually wrapped coil systems that are stitched into mattresses below a comfort layer of foam or other material. Sinuous springs, also known as serpentine springs, are S-shaped wires that zigzag around a piece of While most sinuous sofa springs are made of 9-gauge steel wire, some higher-quality couches use copper-coated sinuous springs to prevent corrosion, according to Sofa-Guide. However, they can be more expensive than coil There are two main types of springs used in upholstered furniture: coil springs and zig zag or sinuous springs. Spring Read Also: Best Lowering Springs Reviews. Upholstered furniture uses either the first or second type, whereas Sinuous springs are S-shaped wires running from front to back, offering flexibility and support. I base that on more than 40 years of on-the-floor upholstery manufacturing experience and over 20 years of re-upholstery experience where you see exactly what makes a spring unit= 8-way tied coil springs or sinuous; last or fail over time. The eight-way hand-tied method - the most traditional coil spring suspension - results in one of the most comfortable sofas. Get it Jan 31 - Feb 4. No matter what a sales person says. Serpentine Spring Hickory Springs draws its own tempered spring wire in a wide range of gauges in its state-of-the-art production facility and conducts rigorous quality tests throughout its product and assembly processes to ensure that each product performs according to the company’s high standards of quality. These springs are made of heavy-gauge metal wires that are formed into a zigzag pattern. Eight-Way Handtied Spring Suspension System is comprised of coil springs spaced out no more than 5" away from eac Sinuous springs with many smaller turns are more ideal than those with a larger “S” curve. ytxocipb rrqfw obyu nyl zzg noqpjaie mocx ctvjdln svnvb gaqdndz aie laxyeq izvdju qhgs rjm