Quick Answer: What Grade Is A Case Hardened Bolt?

What materials can be case hardened?

Case hardening is a material processing method that is used to increase the hardness of the outer surface of a metal….The ferrous metals commonly case hardened are:Low carbon steel.High carbon steel.Cast iron.High strength low alloy steel.Tool steel.Stainless steels..

What grade Bolt is the strongest?

grade 8The strongest commercial-quality bolt is grade 8, marked by six raised dashes; its medium-carbon alloy steel has been quenched and tempered to achieve a tensile strength of 150,000 psi.

What grade is a 12.9 bolt?

Bolt Grade Markings and Strength ChartHead MarkingGrade and MaterialMechanical PropertiesMin. Tensile Strength (psi)Class 10.9 Alloy steel, quenched and tempered1040Class 12.9 Alloy steel, quenched and tempered1220Usually Stamped A-2 or A-4A-2 & A-4 Stainless Steel alloy with chromium and nickel500 Min. 700 Typical18 more rows

How hard is a 10.9 bolt?

Used in automotive applications and for bolting large and forged parts, metric 10.9 bolts exhibit high tensile strength and good wear resistance. … The yield strength of the bolts is 940 and the tensile strength is 1040 MPa.

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.

What does 12.9 mean on a bolt?

The minimum ultimate tensile strength of the Grade 12.9 Metric Hex Head Bolts is about 1242 Mpa or 180,000 PSI, making them the highest grade of bolts produced.In fact, the Grade 12.9 Nuts is known for their high tensile strength.

What is the meaning of 8.8 grade in a bolt?

8.8- This type of grade is often referred to as the structural grade for bolts. … When a bolt has a grading of S, it means that it can withstand a stress of 45 to 49.9 metric tonnes per 6.45 cm². This grading, which is typically stamped on the head of the bolt, has the same tensile strength as a grade 8.8 bolt.

Is it better to quench in oil or water?

Water-quenched steels will generally be harder than oil-quenched steels. This is mainly because the thermal conductivity of water is higher than the thermal conductivity of most oils (that I know); consequently, the rates of cooling will be less rapid (or lower) in oils compared with water.

Is a 10.9 Bolt stronger than Grade 8?

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. A low carbon steel for general use.

Are stainless steel bolts stronger than Grade 8?

Stainless steel bolts are rated for corrosion resistance. 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.

What is the difference between a 10.9 and 12.9 Bolt?

12.9 grade steel has 120% of the tensile strength of 10.9 grade steel. The “12” prefix indicates a tensile strength of X100 N/mm^2 and the “9” suffix indicates a multiplier. Both 12.9 and 10.9 have the same multiplier, so the comparison is straightforward: 12 to 10.

What grade are hardened bolts?

Grade 5Grade 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.

What grade bolt has the highest shear strength?

They are commonly used at high stress points in connecting devices.12.9 Bolts. A 12.9 bolt is one of the highest grade of bolts produced. … 12.9 Shear Strength. The minimum tensile strength of a 12.9 bolt is 1220 MPa.

Will Grade 8 bolts rust?

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 is the difference between Case hardening and surface hardening?

The biggest difference between each process is that case hardening creates a thin layer on the surface. Surface hardening hardens the outer surface and keeps the core soft throughout the entire process.

What is the process of case hardening?

Case-hardening or surface hardening is the process of hardening the surface of a metal object while allowing the metal deeper underneath to remain soft, thus forming a thin layer of harder metal (called the “case”) at the surface.

What is the hardest bolt you can buy?

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.

What grade are ARP bolts?

Explains how ARP polished stainless steel and black oxide finished 8740 bolts are stronger than SAE Grade 5 or Grade 8 fasteners, as well as ISO 8.8 and 10.9 rated metric bolts. ARP accessory bolts are nominally rated at 170,000 psi tensile strength, far superior to the 120,000 of Grade 5 and 150,000 Grade 8 ratings.