What are the product marking requirements for 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.
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
A563 nut specification marking requirements:
|O, A, B||No marking required|
|C||Manufacturers ID plus 3 circumferential lines 120 apart|
|C3||Manufacturers ID plus 3 circumferential lines 120 apart plus numeral 3|
|D||Manufacturers ID plus D|
|DH||Manufacturers ID plus DH|
|DH3||Manufacturers ID plus DH-3 if heavy hex, HX3 if standard hex|
A194 nut specification requires manufacturers identification plus the following grade symbols:
|Grade and Type||Nuts Hot-Forged or Cold-Punched||Nuts Machined from Bar Stock||Nuts Manufactured in Accordance with 6.6|