Astm, sae and iso grade markings for steel fasteners. Bolts are typically marked on the head to show the grade of the bolt and the manufacturers identification. Material, nominal size range mm, mechanical properties. The greater the steels tensile strength, the more torque the bolt can take and the tighter the bolted joint will be. As with any system, the metric system has also been changing and several modifications have been devised to match the progress of. Common automotive fasteners guide napa know how blog. A guide to torque values it should be understood that the subject of torque tension loading is beyond the scope of this document.
Always refer to project specifications and consult an engineer to ensure that your application is appropriate. Allen head bolts can easily be identified as they require the use of an allen wrench. 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. The remainder of the world uses iso metric fasteners almost exclusively, due to their superiority in proportions, fatigue strength, pitch, size and specification. In custom use, thread size, pitch and tolerance classes can be independently selected for custom metric thread dimensions calculations. Metric bolt grade mechanical requirements for carbon steel. As with unified fasteners, metric bolts will be stamped to designate the type of stainless steel that they are made of. Many metric bolts denote the use of metric measurements with an m at the start of the bolt designation, such as m9x1.
I went into depth explaining the different classes of metric bolts and grades of standard bolts. Rather than being stamped with f593cd or f593gh astm specifications for inch series stainless bolts, metric bolts will have a. Stainless hex bolts there are different grades of stainless but the most common are bolts made in the 303 and 304 series of stainless. A short guide to metric nuts and bolts 2 thomson rail. 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. Diameterdecimal metric chart for small diameter fasteners. Metric nuts proof loads proof loads of metric nuts coarse and fine threads. For metric bolts strength is according iso 898 mechanical properties of fasteners made of carbon steel and alloy steel described by property classes with. I explained that the subaru bolt is a metric m10x1. In metric bolts there are 3 commonly used classes, 8. Grade 5 bolts have 3 marks or lines on the head that are in the shape of a y.
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. Did you need to understand metric fastener grades and strength limits. The leader in fasteners, shop supplies, hand tools, and hardware. The markings shown for all grades of a194 nuts are for cold formed and hot forged. Some notes from iso 898 metric screw threads standards. In addition to the indicated grade marking, all grades, except a563 grades o, a and b, must be marked for manufacturer identification. Tensile strength psi mpa us bolts no markings grade. Fasteners smaller than m5, and those with slotted or recessed heads, whatever their diameter, need not be marked. We offer stainless steel threaded rod in a variety of grades and common metric sizes. Hex bolts have hexagonal heads and machine threads for use with a nut or in a tapped hole. Imperial grades ibfin2 psi metric classes mpa nmm2 l9 180,000 psi high tensile. Supplier of metric nuts, bolts, screws, washers and. Iso metric hexagon bolts and screws product grades a and b part 1. Fastener property classes the metric system designates strength capabilities via property classes rather than grades.
The chart below shows metric bolt conversions and din numbers for fasteners. This technical information is supplied as a courtesy. 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. Industry standard allen heads have a tensile strength of 160,000 psi. 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.
Except for the very lowest grades, metric nuts and bolts all carry iden. Product material and treatment tensile yield strength, nmm2 tensile ultimate strength, nmm2 surface, max prod. 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. 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.
We supply metric bolts with coarse, fine and extra fine thread. Higher strength nuts or nuts of equal strength may be a suitable substitute provided bolt standard allows. Identifying bolt grades and head markings for us grades 2, 5 and 8. Externallythreaded fasteners metric series property class. Metric millimeter bolt and nut substitutions will be allowed in accordance with these tables.
Bolt grade markings and strength chart mechanical properties head marking grade and material nominal size range inch mm proof load psi mpa min. The highest metric class for strength, it exceeds grade 8. Bel metric carries a wide inventory of wholesale metric bolts. Tensile strength psi mpa us bolts no markings grade 2 low or medium carbon steel 14 thru 34. Standards for bolt strength grades are set according to a system devised by the society of automotive engineers. This edition has been technically revised and introduces the designations of product grade a and.
Grade 2 bolts a307 are a standard hardware grade steel. Supplier of metric nuts, bolts, screws, washers and fasteners. Some important notes from iso metric thread standards. Nov 19, 20 i thought i would post a few tidbits from the research. 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. If strength is important, ensure that both the grade and manufacturer identification markings are present. 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. There are three common grades for sae fractional and four common grades for metric fasteners. Metric bolts head and wrench sizes ansiso, din and jis bolts. Sae the main classifications are grades 2, 5, 8, allen heads, and stainless. Stainless steel 316 a4 also known as a4 stainless, 316 is a highly corrosion resistant grade of stainless steel. Second, the different grades have a meaning to them.
Under the metric system, each of the eight product types would have its own individual standard. A bolt is a form of threaded fastener with an external male thread. From the original jeepl list to the xjlist to the board, a common question comes. Today, only two systems, inchpound and metric, are predominate in most industrial nations. Choose from our selection of metric bolts, including over 11,300 products in a wide range of styles and sizes. Check out our weekly blog for new posts every monday. Today i want to discuss the mechanical properties of metric fasteners as related under iso 898. Besides using metric measurements, a metric bolt uses the distance between the threads rather than the thread pitch, used in. Metric bolts tightening torques engineering toolbox. Strength grades for metric fasteners are designated by a symbol comprised of 2 numbers, separated by a decimal. Iso metric screw threads are designated by basic diameter and thread pitch. Sud bolt grade petrochemical stud bolts for flanges re astm a193. Includes screws such as pan, button, binding, and truss.
The international organization for standardization iso has established standards for classifying metric bolts and screws into property classes based on strength. Usa grade 5 bolts are the most common bolts found in automotive and other applications. Order your metric bolts today bel metric has metric hex bolts, class 10. In metric bolts, strength is described by property classes. Performance data listed are for standard production items only. This standard is part 1 of a twopart series on iso metric hexagon bolts and screws.
The user shall use 6g for bolts and 6h for nuts unless there is a specific requirement to use other tolerance classes. Metric bolts minimum ultimate tensile and proof loads minimum ultimate tensile and proof loads for metric bolts with coarse or fine threads. Plain black metric socket head cap screws with coarse thread grade 12. The information here supplied is an acceptable guide for normal conditions. Understanding fastener grades and classes fastener mart. 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. Why specified torque is sometimes lower than the maximum. Select models are available in zinc, yellow and black plate. Metric bolt conversion to standard bolt conversion chart. The distinction between a bolt and a screw is commonly misunderstood. First, you need to be able to identify bolts by the different grades when you go to the local hardware store.
Head marking class and material nominal size range mm mechanical. Belmetric carries a wide inventory of wholesale metric bolts. The higher the iso numbers are, the stronger the bolt. Stainless is often used as threaded studs, tie rods, u bolts and hooks. 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. Standards for metric bolts are promulgated by the iso, but adopted by individual nations dimensions. A domed head sits above the surface of your material. The metric system has its own unique way of marking and designating stainless steel fasteners. On the head of each bolt are two numbers separated by a decimal point, the full list includes ten grades from 3. Bolts are also specified for strength, known as grade for sae or class for metric. 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. 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.
Alternate systems exist for unified inch series bolts and screws in carbon and alloy steels. Radial lines, such those used to mark sae grades, are never used on metric bolts. These bolts are the common shiny silver zinc bolts that are used for general purposes. 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. Nonstock items may vary due to variables in methods of manufacture. Choose from our selection of metric stainless steel bolts, including hex head screws, socket head screws, and more. Metric bolt conversion data for industrial bolts rods, machine screws and small diameter fasteners from raaj sagar steels includes metric to standard bolt conversions.
Metric bolt conversion data for industrial boltsrods, machine screws and small diameter fasteners from raaj sagar steels includes metric to standard bolt conversions. A short guide to metric nuts and bolts dd thomson rail. The metric system designates strength capabilities via property classes rather than grades. 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. They are available in coarse, fine, and extra fine thread. As soon as this work was completed, a specification was drafted.
The first number represents 1100 of the nominal tensile strength in nmm2. Stainless steel 188 a2 also known as a2 stainless, 188 is the most common grade of stainless steel for general use. Strength grades for metric fasteners are designated by a symbol. A table of major diameters and pitches, up to 30 mm in diameter thread classes of fit. In this video, one of our resident fastener specialists talks about the types of materials fasteners screws, nuts, bolts, washers, etc are available in. Usa grade 8 bolts are alloy and are stronger than grade 5 bolts. Metric threaded rod stainless steel grades metric metal.
Choose from metric hex, flange and lock nuts with coarse or fine thread. The correct match for a nut used with bolts of property class 10. This australian standard was prepared by committee me29, fasteners. The tables below are provided as a general guide to help you better understand metric and imperial measurements. There are also lower grade metric bolts which should be avoided. No substitution will be allowed for any a325 bolts supplied under 71514 and used for structural connections on bridges, unless approved by the dces. Grade5 is identified by three bars on the head and grade8 by 6 bars on the head. Bolts and screws also bear a mark to identify the manufacturer. Use these general purpose screws for a variety of fastening applications. Diameterdecimalmetric chart for small diameter fasteners.
850 477 423 951 224 1317 1488 685 1078 402 438 318 182 1149 736 228 918 1306 1254 232 1407 589 22 737 1265 339 1085 610 961 583 903 34 411 1251 423 852 726 927 1160 1496 768