Double-End Studs DIN 835 (GB/T 901-1988)

This is the GB/T 901 double-end stud product page. GB/T 901 is the Chinese standard for equal-length double-end studs (product grade B); DIN 835 is registered in our standard-alias table as the common commercial equivalent, with the engagement-end thread length (bm = 2d) confirmed on order. We supply to GB/T 901, in sizes M8–M30, in carbon steel 8.8, alloy steel 10.9, 35CrMo and stainless 304 (A2-70).

ASTM A193 B7 / A320 L7 comparison (material-grade standards, not dimensional standards): ASTM A193/A193M is the material and mechanical-property specification for alloy-steel and stainless-steel bolting for high-temperature or high-pressure service. Grade B7 is heat-treated AISI 4140/4142 chromium-molybdenum alloy steel with a minimum tensile strength of 125 ksi and minimum yield of 105 ksi up to 2-1/2 in., and A193 does not cover low-temperature service. ASTM A320/A320M is the low-temperature companion: it parallels A193 in materials, and Grade L7 shares the same chemistry (AISI 4140/4142) and the same mechanical properties as B7, with an added mandatory Charpy V-notch impact test at -150 °F (-101 °C). Published spec guidance puts the A193/A320 split at -20 °F / -29 °C: below that, A320 is the standard specified.

One point worth stating plainly: A193 / A320 specify material and mechanical properties — they do not specify stud diameter, length or thread dimensions. The correspondence on this page is an application-scenario (high-temperature / low-temperature) grade selection, not a dimensional equivalence. Stud dimensions still follow GB/T 901 or your drawing; where you need B7 / L7 grades, state the grade and the certificate requirements (e.g. MTC / EN 10204) at inquiry and we will confirm per project.