This bolt here which is a hot dip galvanized alloy bolt It has again the manufacturers markings the XYLX and then it says 307A 307A is the indication of the strength of the bolt Basically this is equal to like a carriage bolt strength a grade 2 or better a little bit better than a grade 2 but standard alloy These are not heat treated 8 6 2018 nbsp 0183 32 However as you can see in the following table both tension and shear are higher in Grade 8 bolts over Grade 5 bolts in fact over 21 higher in shear and 25 in tension The same is true in metric when comparing 8 8 vs 10 9 To be fair the higher the grade of bolt the harder it becomes as rated by the rockwell scale Strength Structural Bolts Alloy Steel Quenched and Tempered 1 2 thru 1 1 2 120 000 130 000 150 000 min 170 000 max No Grade Mark ISO R898 Class 4 6 Bolts Screws Studs Medium Carbon Steel Quenched and Tempered All Sizes thru 1 1 2 33 000 36 000 60 000 ASTM SAE AND ISO BOLTING MATERIAL Page 5 Identifi cation Grade MarkShear Strengths Comparison Grades 2 5 amp 8 Comparison of Shear Strengths of Grade 2 5 and 8 Screws The industry standard for determining shear strengths of fasteners is to take 60 of the minimum Ultimate Tensile Strength of the fastener for d For structural bolting 70000 N M12 95500 N M14 and 130000 N M16 Mass and Weight the difference Bolt Torque Calculator US Bolts Tensile Strength and Proof Loads Proof Load Proof load is defined as the maximum tensile force that can be applied to a bolt that will not result in plastic deformation

On the other hand compared to threaded bolts they are cumbersome and time consuming to install and remove and offer limited clamp load However securing a threaded bolt with a Nord Lock washer ensures resistance to vibration and also makes it 5 11 2019 nbsp 0183 32 Metric Bolt Class Mechanical Properties Proof Load MPa Min Yield MPa Min Tensile Strength MPa Class 12 9 Alloy Steel quenched and tempered 970 1 100 1 220 Class 10 9 Alloy Steel quenched and tempered 830 940 1 040 Class 8 8 Medium carbon steel quenched and tempered 580 600 640 660 800 830 A4 80 Stainless20 rows nbsp 0183 32 Yield strength is stress at which a permanent set of 0 2 of gage length occurs Tensile strength and proof loads SAE bolts Grade 2 Low Carbon Steel up to 3 4 quot proof load 55000 psi minimum tensile strength 74000 psi 3 4 quot 1 1 2 quot proof load 33000 psi minimum tensile strength 66000 psi Grade 5 Medium Carbon Steel Quenched and Tempered up to 1 quot proof load 85000 psi 1 quot 1 1 2 quot proof load 74000 psi minimum tensile strength 105000 psiThese metric bolt torque charts show the ideal tightening torque for class 8 8 10 9 and 12 9 bolts for both wet and dry tightening The bolt s class indicates its material strength with higher numbers meaning higher tensile and yield strength The classes are set by the International Standards Organisation or ISO

10 11 2020 nbsp 0183 32 The difference between ordinary bolt and high strength bolt Normal bolts are reusable high strength bolts are not reusable High strength bolts are generally made of high strength steel 45no steel 8 8s 20MmTiB 10 9S are pre stressed bolts the friction type requests torque wrench to apply the specified pre stress and the pressure type requires the The bolts of this grade with a nominal size range from 1 4″ to 3 4″ have a minimum tensile strength of about 57000 psi and the yield strength of sizes from 3 4″ to 1 2″ 36000 psi Grade 5 – Unlike grade 2 bolts grade 5 bolts feature 5 radial lines These bolts are manufactured from medium carbon steel 5 6 2020 nbsp 0183 32 Grade 8 bolts have a minimum tensile strength of 150 000 PSI As a comparison the ASTM A325 bolt is roughly equivalent to the SAE grade 5 A grade 8 bolt would be one that meets ASTM A490 standards The A325 bolt strength or SAE grade 5 bolt strength is usually used for structural bolting projects 17 rows nbsp 0183 32 1200 Stainless Steel Class 120 e g Bumax 129 Stainless Steel Class 120 1200 5 11 2019 nbsp 0183 32 Head Markings Metric Bolt Class Mechanical Properties Proof Load MPa Min Yield MPa Min Tensile Strength MPa Class 12 9 Alloy Steel quenched and tempered 970 1 100 1 220 Class 10 9 Alloy Steel quenched and tempered 830 940 1 040 Class 8 8 Medium carbon steel quenched and tempered 580 600 640 660 800 830 A4 80 Stainless Similar to

The yield strength of a bolt can be defined as the tensile force that will produce a certain amount of permanent deformation within a specific fastener In many but not all bolting situations it s important not to tension a bolt past its yield strength because it no longer retains its original size and shape and ultimately its performance in a bolted joint 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 6 4 8 5 8 8 8 9 8 10 9 and 12 9 Therefore it is important for critical strength applications that the actual yield strength of a sample in its final form be measured For a comparison of specialty metal tensile and yield data see Figure 2 and for more complete information visit our high strength fasteners pages at Extreme Bolt amp Fastener Grade 5 bolts are hardened to increase strength and are the most common bolts found in automotive applications Grade 5 bolts have 3 evenly spaced radial lines on the head Grade F is roughly equivalent to Grade 5 Grade F nuts are used with Grade 5 bolts Grade 8 Grade GFastener Tensile Strength Tensile Strength is the most widely associated threaded fastener mechanical property and is the maximum tension applied load the fastener can support prior to its fracture it is also called Ultimate tensile strength UTS Strength systems for bolts are based on levels of their ultimate tensile strength this is when a bolt is subject to stretching along its

How strong are bolts compared to welding and what qualities to look for in foundations Ask Question Asked 10 years 8 months ago A welded connection can always be made the same strength as the original steel by using a full penetration but weld but this all depends on the quality of the materials used for the welding and the quality of 8 1 1993 nbsp 0183 32 In general the stress area of fine pitch thread bolts passing through the threaded part is larger as compared to the coarse pitch thread bolts The calculated strength properties for coarse pitch thread bolts may be used conservatively for fine pitch thread bolts 28 10 2018 nbsp 0183 32 A bolt on the other hand is not self tapping and requires a nut to stay secure Screws and bolts also differ in shape and cost screws are often tapered while bolts are not and bolts tend to cost more than screws 2 Is a Bolt Stronger Than a Screw Yes bolts provide greater holding strength than screws Tensile Strength Comparison Chart Tensile Strength is the maximum tension applied as loading that a fastener can support prior to or coincidental with its fracture Imperial Ibf in2 MPa Metric 1200 Stainless Steel Class 120 e g Bumax 129 1 3 2012 nbsp 0183 32 A quick question are you replacing 19mm 316 bolts that were originally fitted If so as I mentioned before these may in fact have been stronger material strength than the 2205 that you are looking at Then there is also the difference in strength between a rolled thread if the bolts were a mass produced item and a cut thread