Thread Rolling Materials

Material Preparation

Blank diameter tolerance for common threads is about 1/3 the pitch diameter tolerance. If the outside tolerance is less than twice the pitch diameter tolerance, the blank should be held to within 1/6 the pitch diameter tolerance.

Test rolling should always be used to determine actual blank diameter needed before producing blanks in quantity, or ordering large quantities of sized rolling materials.

Mild steel bars are usually rolled without chamfering ends of bars. As hardness increases, chamfering should be considered to increase die life. When approaching the 30 RC range and harder, chamfering is needed or die life will shorten considerably. The harder the material, the flatter the chamfer needed, and the chamfer should be slightly below the root diameter of the rolled thread.

Typical Thread Finishes for Average Threads

Rolled Threads-4-32m/in.
Ground Threads-16-32m/in.

1005 - 1095 Low Carbon Steel

This type of steel is very desirable and one of the most widely used types of steel.

12L14, 12L15, 11L17, and 11L41

These steels roll satisfactorily in vee threads, but are not good for deep and wide forms due to the high lead content.

1111 - 1144

These steels are free machining (high sulfur), and have the tendency to flake with acme and other wide root forms.

40 Series Alloy

40 Series Alloy steels roll well and give an excellent finish, but die life decreases as toughness and hardness increase.

Stainless Steel

304 - 316 stainless steel work hardens giving poor die life, but rolls well. Work finishes with a very small crest seam.

403 - 416 stainless steel has better die life, rolls good but leaves a larger crest seam.

Cartridge Brass

This is the top of the line for rolling. Other brass will roll, but the finish may not be as good as what this brass gives