Din931 Grade 10.9

Class 10.9 Bolts

Description

A bolt with metric thread pitch made from medium carbon alloy steel and heat-treated. Grade-A bolts are the preferred style for most applications. Grade-B bolts have looser tolerances and can be manufactured in a cold or hot-forging process.

Applications/Advantages

Has greater tensile strength than Class 8.8 bolts; is most comparable but not exactly equivalent to U.S. Grade 8 cap screws.

Material

Class 10.9 bolts can be made from a carbon steel which conforms to the following chemical composition-- Carbon: 0.25-0.55%;

Phosphorus: 0.035% maximum; Sulfur: 0.035% maximum.

Class 10.9 bolts can be made from a low carbon martensite steel with additives (such as Boron, Manganese or Chromium) which

conforms to the following chemical composition-- Carbon: 0.20-0.55%; Phosphorus: 0.035% maximum;Sulfur: 0.035% maximum. In case of plain carbon boron alloyed steel with a carbon content 0f less than 0.25% (ladle analysis), the minimum Manganese content shall be 0.7%

Class 10.9 bolts can be made from an alloy steel which conforms to the following chemical composition--

Carbon: 0.20-0.55%; Phosphorus: 0.035% maximum; Sulfur: 0.035% maximum; and shall contain one or more of the following

elements: Chromium, Nickel, Molybdenum or Vanadium

Heat Treatment

Class 10.9 bolts shall be heat treated by quenching in oil from above the transformation temperature and reheating to a tempering

temperature of 425°C.

Core Hardness

Rockwell C32 - 39 (Vickers HV 320 - 380)

Surface Hardness

Shall not be more than 30 Vickers points above the measured core hardness on the product

Proof Load

940 N/mm2 minimum

Tensile Strength

1040 N/mm2 minimum

Elongation

9% minimum

Plating

Zinc,HDG,Plain,Dacrotized,Teflon,Colorful Dye