Externallythreaded fasteners metric series property class. If strength is important, ensure that both the grade and manufacturer identification markings are present. In metric bolts there are 3 commonly used classes, 8. Understanding fastener grades and classes fastener mart. Always refer to project specifications and consult an engineer to ensure that your application is appropriate. Hex bolts have hexagonal heads and machine threads for use with a nut or in a tapped hole.
In metric bolts, strength is described by property classes. Check out our weekly blog for new posts every monday. A table of major diameters and pitches, up to 30 mm in diameter thread classes of fit. For metric bolts strength is according iso 898 mechanical properties of fasteners made of carbon steel and alloy steel described by property classes with designations 4. Astm, sae and iso grade markings for steel fasteners. Material, nominal size range mm, mechanical properties. Metric bolt conversion to standard bolt conversion chart. The first number represents 1100 of the nominal tensile strength in nmm2. As soon as this work was completed, a specification was drafted. Iso metric hexagon bolts and screws product grades a and b part 1. There are three common grades for sae fractional and four common grades for metric fasteners. Industry standard allen heads have a tensile strength of 160,000 psi. Bolts are typically marked on the head to show the grade of the bolt and the manufacturers identification.
Today, only two systems, inchpound and metric, are predominate in most industrial nations. This edition has been technically revised and introduces the designations of product grade a and. Stainless hex bolts there are different grades of stainless but the most common are bolts made in the 303 and 304 series of stainless. Performance data listed are for standard production items only. As with any system, the metric system has also been changing and several modifications have been devised to match the progress of. The tables below are provided as a general guide to help you better understand metric and imperial measurements. Metric bolts tightening torques engineering toolbox. Radial lines, such those used to mark sae grades, are never used on metric bolts. Bolt grades i have been on a quite a few online email lists over the last 7 years or so, basically since they first came out. Bolts and screws also bear a mark to identify the manufacturer. Select models are available in zinc, yellow and black plate. The markings shown for all grades of a194 nuts are for cold formed and hot forged.
Nov 19, 20 i thought i would post a few tidbits from the research. This standard is part 1 of a twopart series on iso metric hexagon bolts and screws. Strength grades for metric fasteners are designated by a symbol comprised of 2 numbers, separated by a decimal. Grade identification markings inch steel bolts grade marking specification description material nominal size inches proof load psi tensile strength min psi yield strength min psi rockwell hardness min max sae j429 grade 1 bolts, screws, studs low or medium carbon steel 14 1 12 33000 60000 36000 b70 b100 sae j429 grade 2 bolts. I went into depth explaining the different classes of metric bolts and grades of standard bolts. Mechanical properties proof load psi yield strength min psi tensile strength min psi no grade mark sae j429grade 1 bolts, screws, studs low or medium carbon steel 14 thru 112 33,000. Choose from metric hex, flange and lock nuts with coarse or fine thread. Belmetric carries a wide inventory of wholesale metric bolts. Standards for metric bolts are promulgated by the iso, but adopted by individual nations dimensions. Grades and head markings metric the kind of steel bolts and screws are made of and the treatment they receive during manufacture determine their strength.
For metric bolts strength is according iso 898 mechanical properties of fasteners made of carbon steel and alloy steel described by property classes with. Choose from our selection of metric stainless steel bolts, including hex head screws, socket head screws, and more. Identifying bolt grades and head markings for us grades 2, 5 and 8. Standards for bolt strength grades are set according to a system devised by the society of automotive engineers.
Fasteners smaller than m5, and those with slotted or recessed heads, whatever their diameter, need not be marked. Diameterdecimal metric chart for small diameter fasteners. Bel metric carries a wide inventory of wholesale metric bolts. Metric millimeter bolt and nut substitutions will be allowed in accordance with these tables. Some notes from iso 898 metric screw threads standards. Order your metric bolts today bel metric has metric hex bolts, class 10. Metric bolts head and wrench sizes ansiso, din and jis bolts.
Stainless is often used as threaded studs, tie rods, u bolts and hooks. Metric bolt grades and strength calculator to show proof strength, tensile strength, vickers brinell hardness, minimum breaking torque and stress area of metric bolts and screws made of carbon steel and alloy steel with designations 4. Some important notes from iso metric thread standards. Stainless steel threaded rod is necessary when the material will be exposed to chemicals, salt water or extreme temperature because of its corrosion and temperature resistance. We supply metric bolts with coarse, fine and extra fine thread. From the original jeepl list to the xjlist to the board, a common question comes. We offer stainless steel threaded rod in a variety of grades and common metric sizes.
The information here supplied is an acceptable guide for normal conditions. The greater the steels tensile strength, the more torque the bolt can take and the tighter the bolted joint will be. Plain black metric socket head cap screws with coarse thread grade 12. The remainder of the world uses iso metric fasteners almost exclusively, due to their superiority in proportions, fatigue strength, pitch, size and specification. Except for the very lowest grades, metric nuts and bolts all carry iden. The distinction between a bolt and a screw is commonly misunderstood. Many metric bolts denote the use of metric measurements with an m at the start of the bolt designation, such as m9x1. A short guide to metric nuts and bolts dd thomson rail. A short guide to metric nuts and bolts 2 thomson rail.
Besides using metric measurements, a metric bolt uses the distance between the threads rather than the thread pitch, used in. In addition to the indicated grade marking, all grades, except a563 grades o, a and b, must be marked for manufacturer identification. These bolts are the common shiny silver zinc bolts that are used for general purposes. Mar 01, 2017 in this video, one of our resident fastener specialists talks about the types of materials fasteners screws, nuts, bolts, washers, etc are available in.
Besides using metric measurements, a metric bolt uses the distance between the threads rather than the thread pitch, used in american measurements, which is the number of. In custom use, thread size, pitch and tolerance classes can be independently selected for custom metric thread dimensions calculations. The metric system designates strength capabilities via property classes rather than grades. Usa grade 5 bolts have three evenly spaced radial lines on the head, and the material is similar in strength to european metric class 8. Bolt grade markings and strength chart mechanical properties head marking grade and material nominal size range inch mm proof load psi mpa min. A guide to torque values it should be understood that the subject of torque tension loading is beyond the scope of this document. Fastener property classes the metric system designates strength capabilities via property classes rather than grades. Metric bolt conversion data for industrial boltsrods, machine screws and small diameter fasteners from raaj sagar steels includes metric to standard bolt conversions.
Usa grade 8 bolts are alloy and are stronger than grade 5 bolts. Because there are so many different grades and fasteners all look about the same, medium carbon and alloy steel strength grades are marked for identification. Metric bolt grade mechanical requirements for carbon steel. The chart below shows metric bolt conversions and din numbers for fasteners.
Metric steel bolts grades and property classes metric steel bolts, screws and studs proof and tensile strength threaded bolt stress area threaded bolts tensile stress area threaded rods loads in imperial units weight rating of threaded hanger rods. Download a complimentary pdf of our fastener markings chart. Metric nuts proof loads proof loads of metric nuts coarse and fine threads. Allen head bolts can easily be identified as they require the use of an allen wrench. Grade 2 bolts a307 are a standard hardware grade steel. Tensile strength psi mpa us bolts no markings grade. I explained that the subaru bolt is a metric m10x1.
A short guide to metric nuts and bolts answers to the most frequently asked questions standard and fine pitch th reads how to identify nut and bolt strength grades how nut and bolt strength grades compare maximum tightening torques why specifi ed torque is sometimes lower than the maximum spanner sizes versus bolt nut thread size. Tensile strength psi mpa us bolts no markings grade 2 low or medium carbon steel 14 thru 34. Today i want to discuss the mechanical properties of metric fasteners as related under iso 898. Rather than being stamped with f593cd or f593gh astm specifications for inch series stainless bolts, metric bolts will have a. This technical information is supplied as a courtesy. Includes screws such as pan, button, binding, and truss. On the head of each bolt are two numbers separated by a decimal point, the full list includes ten grades from 3. In this video, one of our resident fastener specialists talks about the types of materials fasteners screws, nuts, bolts, washers, etc are available in. Contact american fastener with any questions or for a custom quote.
Sae the main classifications are grades 2, 5, 8, allen heads, and stainless. Common automotive fasteners guide napa know how blog. Grade 5 bolts have 3 marks or lines on the head that are in the shape of a y. Under the metric system, each of the eight product types would have its own individual standard. Product material and treatment tensile yield strength, nmm2 tensile ultimate strength, nmm2 surface, max prod. Imperial grades ibfin2 psi metric classes mpa nmm2 l9 180,000 psi high tensile. They are available in coarse, fine, and extra fine thread. Stainless steel 188 a2 also known as a2 stainless, 188 is the most common grade of stainless steel for general use. The leader in fasteners, shop supplies, hand tools, and hardware. Metric threaded rod stainless steel grades metric metal. Strength grades for metric fasteners are designated by a symbol. The metric system has its own unique way of marking and designating stainless steel fasteners.
The higher the iso numbers are, the stronger the bolt. There are also lower grade metric bolts which should be avoided. Metric bolt conversion data for industrial bolts rods, machine screws and small diameter fasteners from raaj sagar steels includes metric to standard bolt conversions. Did you need to understand metric fastener grades and strength limits. The international organization for standardization iso has established standards for classifying metric bolts and screws into property classes based on strength. Iso metric screw threads are designated by basic diameter and thread pitch. Use these general purpose screws for a variety of fastening applications.
No substitution will be allowed for any a325 bolts supplied under 71514 and used for structural connections on bridges, unless approved by the dces. As with unified fasteners, metric bolts will be stamped to designate the type of stainless steel that they are made of. This australian standard was prepared by committee me29, fasteners. Higher strength nuts or nuts of equal strength may be a suitable substitute provided bolt standard allows. The user shall use 6g for bolts and 6h for nuts unless there is a specific requirement to use other tolerance classes. First, you need to be able to identify bolts by the different grades when you go to the local hardware store. Nonstock items may vary due to variables in methods of manufacture. Metric bolts minimum ultimate tensile and proof loads minimum ultimate tensile and proof loads for metric bolts with coarse or fine threads. Why specified torque is sometimes lower than the maximum. Compatible denotes commercially available nut having suitable mechanical properties and dimensional configuration or style which will make it possible to obtain the desired bolt load. Stainless steel 316 a4 also known as a4 stainless, 316 is a highly corrosion resistant grade of stainless steel.
Bolts are also specified for strength, known as grade for sae or class for metric. Alternate systems exist for unified inch series bolts and screws in carbon and alloy steels. Diameterdecimalmetric chart for small diameter fasteners. The highest metric class for strength, it exceeds grade 8. Supplier of metric nuts, bolts, screws, washers and fasteners. Grade5 is identified by three bars on the head and grade8 by 6 bars on the head. Choose from our selection of metric bolts, including over 11,300 products in a wide range of styles and sizes. The correct match for a nut used with bolts of property class 10. A domed head sits above the surface of your material. Supplier of metric nuts, bolts, screws, washers and. Apr 28, 2009 hex head bolts m5 and larger must have the property class marked on the head of the bolt, either in raised or depressed lettering. Usa grade 5 bolts are the most common bolts found in automotive and other applications. A bolt is a form of threaded fastener with an external male thread.
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