Frequently Asked Question

What are the product marking requirements for bolts?

Headed bolts are required to be stamped on top of the head, while most rods and some bent bolts are required to be stamped on one end.

This Fastener Identification Markings Chart shows the various marking requirements for most common grades of ASTM and SAE fasteners.

B7 Hex Head BoltHeaded Bolts

ASTM specifications require a manufacturer’s identification and ASTM grade to be permanent and either raised or indented. Fastener specification SAE J429 requires a manufacturer’s identification and nothing else on Grade 2, 3 radial lines on grade 5, and 6 radial lines on grade 8.

ASTM F1554 headed anchor bolts are the exception, as these bolts are color-coded on the threaded end projecting from the concrete. Permanent stamping with manufacturer’s identifier and/or grade symbol is a supplemental requirement of the specification and is only necessary when requested in the purchase order. Permanent marking of the bolt head is not required.

Rods and Studs

Most grades of threaded rods 3/8” diameter and larger (all thread, thread each end, or thread one end) possess the same stamping requirements as headed bolts, with the grade symbol and manufacturer’s identifier required on one end only. ASTM F1554 anchor rods only require color coding on the end projecting from the concrete unless permanent identification is requested on the purchase order.

Bent Bolts

Marking requirements on bent anchor bolts, U-bolts, eye bolts, etc. are somewhat subjective. Portland Bolt chooses to permanently mark any high strength (quenched and tempered) bent fastener that we manufacture, so that it can be easily identified, since most high strength bolts are used in critical applications. These markings again include our manufacturer’s identification and the grade symbol. The exception is ASTM F1554 which is color-coded unless permanent marking is specified.

ASTM A320 Grades L7 and L43 also requires that the Charpy testing temperature be marked on the head of a bolt or end of a threaded rod if the testing is performed at a service temperature that is less than -150 degrees.

Marking Requirements on Nuts

Certain grades of ASTM A563 and A194 hex nuts and heavy hex nuts require grade identification and manufacturer’s identification as follows:

A563 nut specification marking requirements:

GradeRequired marking
O, A, BNo marking required
CManufacturers ID plus 3 circumferential lines 120 apart
C3Manufacturers ID plus 3 circumferential lines 120 apart plus numeral 3
DManufacturers ID plus D
DHManufacturers ID plus DH
DH3Manufacturers ID plus DH-3 if heavy hex, HX3 if standard hex

A194 nut specification requires manufacturers identification plus the following grade symbols:

Grade and TypeNuts Hot-Forged or Cold-PunchedNuts Machined from Bar StockNuts Manufactured in Accordance with 6.6
111B-
222B-
2HB2H2HB-
2HMB2HM2HMB-
333B-
444B-
4LC4L4BL-
666B-
6F6F6FB-
777B-
7LC7L7BL-
7MB7M7MB-
888B8A
8C8C8CB8CA
8M8M8MB8MA
8T8T8TB8TA
8F8F8FB8FA
8P8P8PB8PA
8N8N8NB8NA
8MN8MN8MNB8MNA
8R8R8RB8RA
8S8S8SB8SA
8LN8LN8LNB8LNA
8MLN8MLN8MLNB8MLNA
8MLCuN8MLCuN8MLCuNB8MLCuNA
9C9C9CB9CA
161616B-

Written ,

4 comments

    @Felix- A194 Grade 8R is the designation for nuts made from UNS 20910 stainless, commonly known as Nitronic 50. We are not aware that the R stands for anything specific.

    Dear Sir ,
    Good evening
    We would like to know the prices for the complete machine for producing the rods , headed bolts and other types . The size is from 14mm-20mm.

    Thanks,
    M.zaki

    @Mzaki- We don’t have a price list, we quote all our jobs on a per order basis. If you would like to send your specific requirements, we’d be happy to take a look at it. We would be able to quote an imperial conversion, as we cannot manufacture metric sizes.

Leave a Reply

Your email address will not be published. Required fields are marked *