Bolt Head Grade/Strength Identifiers
| US (English) Bolts | ||
|---|---|---|
| Metric Bolts | ||
| Class and Material | Nominal Size Range (mm) | Min. Tensile Strength (MPa) |
| Class 8.8 – Medium carbon steel, quenched and tempered | Up to 16mm | 800 |
| 16-72mm | 830 |
Is Grade 8 or 8.8 Stronger?
Table 1.
| Grade/Class | Strength |
|---|---|
| Grade 5 | Medium strength. |
| Grade 8 | High strength. |
| Metric Class 4 | Similar to Grade 2. |
| Metric Class 8.8 | Similar to Grade 5. |
What is the difference between 8.8 and 10.9 bolts?
Class 10.9 is stronger than class 8.8. It is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8.
Is 8.8 A high tensile bolt?
High tensile steel bolts
Grade 8.8 high tensile steel is often referred to as the structural grade for bolts. It is the most common form of high tensile material and is usually stocked in plain finish or zinc.
Is an 8.8 bolt a grade 8 bolt?
In terms of strength, 8.8 is equivalent to Grade 5, 10.9 is equivalent to grade 8. There are also 12.9 metric bolts, which are a little stronger than 10.9, and are a higher alloy steel.
What is the strongest bolt?
Grade 9 structural bolts, also known as grade 9 hex cap screws, are one the strongest structural bolts that can be used today. While the typical grade 8 bolt has a tensile strength of 150,000 PSI, a grade 9 bolt has a tensile strength of 180,000PSI.
How strong is a grade 8.8 bolt?
Bolt Grade Markings and Strength Chart
| Grade and Material | Mechanical Properties |
|---|---|
| Min. Tensile Strength (psi) | |
| Class 8.8 Medium carbon steel, quenched and tempered | 800 |
| 830 | |
| Class 10.9 Alloy steel, quenched and tempered | 1040 |
How strong is a metric 8.8 bolt?
Metric steel bolts, screws and studs – proof and tensile strength.
| Property Class | Size Range (mm) | Minimum Tensile Strength (106 Pa) |
|---|---|---|
| 8.8 | M1.6 – M36 | 830 |
| 9.8 | M1.6 – M16 | 900 |
| 10.9 | M5 – M36 | 1040 |
| 12.9 | M1.6 – M36 | 1220 |
How do you read metric bolt grades?
Strength Grades for metric fasteners are designated by a symbol comprised of 2 numbers, separated by a decimal. For example, 4.6 and 8.8. The first number represents 1/100 of the nominal tensile strength in N/mm^2.
How much weight can a 8.8 bolt hold?
In round terms it is in 10’s of kg per square millimeter of the bolt. For example, a grade 12.9 bolt will not snap until every square millimetre of the bolt cross section is carrying a load of at least 120 kg. Similarly a grade 8.8 bolt will not snap until it is carrying a load of 80kg per square millimetre.
What steel is used for 8.8 bolts?
medium carbon steel
The specification Bs 3692 Grade 8.8 standard fasteners are manufactured using medium carbon steel. This medium carbon steel has been treated to heat by both quenching and tempering.
What does 1364 mean?
IS 1364 was originally published in 1960 and first revised in 1967. Subsequent to the publication of 1967 edition, many changes had been agreed upon at international level which have been reflected in IS 1367 series of standards covering ‘Technical supply conditions for threaded steel fasteners‘.
Is 8.8 bolt stainless steel?
Grade 8.8 Bolts belong to the DIN 933 grade 8.8 standard. This is a structural grade for bolts. This is a medium carbon steel bolt specification. These bolts are heat treated by quenched and tempered methods.
What size is an 8.8 screw?
8mm x 1.0mm x 60mm
Metric hex bolts, Zinc plated class 8.8 steel, 8mm x 1.0mm x 60mm.
Is a grade 8 bolt stronger than stainless steel?
Bolt strength is rated in PSI (pounds per square inch). A stainless steel bolt has the same PSI rating as a grade 5 bolt (125,000 PSI). A grade 8 bolt has a stronger rating with a PSI of 150,000.
Is there a grade 10 bolt?
Class 10. This is a metric nut grading similar to the SAE grade 8 classification, which is used in conjunction with Class 10.9 bolts. This strength of nut is used in automotive, and structural industries, as well as in high temp applications.
How strong is a grade 8 bolt?
The nominal size of the grade 8 bolts can be from 1/4″ to 1 1/2″. The minimum yield strength of this grade bolt is 130,000 psi. A maximum of 120,000 psi of tensile force (proof load) can be applied to grade 8 bolts.
Will Grade 8 bolts rust?
Grade 8 Steel Bolts
Grade 8 bolts have 6 evenly spaced radial lines on the head.” Unlike stainless steel, which is highly resistant to corrosion, steel, however reinforced, will oxidize over time and rust. Grade 8 bolts that are not galvanized or plated with yellow zinc, however, are cheaper.
What’s the difference between 4.6 and 8.8 bolts?
Category 4.6/S refers to commercial bolts of Property Class 4.6 conforming to AS 1111.1 tightened using a standard wrench to a ‘snug-tight’ condition. Category 8.8/S refers to any bolt of Property Class 8.8, tightened using a standard wrench to a ‘snug- tight’ condition in the same way as for category 4.6/S.
What is a 9.8 bolt?
A metric bolt designated as ISO class 6.8 roughly corresponds in strength to an SAE Grade 2 bolt. Bolts of ISO class 8.8 and the slightly stronger class 9.8 roughly correspond to an SAE Grade 5 bolt. An ISO Class 10.9 bolt roughly corresponds to an SAE Grade 8 bolt.
What are the strongest screws?
The world’s strongest bolts are stainless. BUMAX® Ultra has proven itself as the world’s strongest bolt – in various highly-demanding critical fastener applications around the world where standard fasteners are simply inadequate.
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