Square Neck, Carriage, Plow, Bumper Bolts

Auto Bolt manufactures carriage bolts, square neck bolts, plow bolts to the customer’s print or specification. Special dimensions, such as head heights, head types, and thread lengths, can be produced. Configurations are available in either inch or metric sizes. Special tooling can be created to produce nonstandard headmarks.

Bumper bolts are manufactured to print to meet your specific needs in inch or metric sizes. We do not provide the capping for these items.

Size Ranges
Inches Metric
Diameter Range 1/4" - 1 1/8" M6 - M27
Length Range - Carriage Bolts 3/8" - 11 3/4"
Standard Materials
Description
Carbon Steels SAE 1008, 1010, 1018, 1038, 1335, 1541, and 10B21
Alloy Steels SAE 4037, 4140, 5140, 8620, 8637, and 8740
Stainless Steels 302, 304, 316, 300 & 400 Series
Coatings
Options Zinc, zinc yellow, phos & oil, black oxide, cadmium, and organics. Other coatings on request.
Manufacturing
Standards Auto Bolt manufactures certified quality products using industry standards such as ASTM, ASME, ANSI, SAE, ISO, and DIN.
Order Quantity In many instances we are able to manufacture 2,500 pieces, depending on the diameter and geometry of the part.