Machine screws nuts manufactured domestically by Amerifast Corp. and MRL Mfg.
All nuts are made of 304 Stainless and are stamped with Robbins "R" trademark and "304AN"; AN stands for annealed. Chemicals and physicals showing conformance to MS specifications are available on all items.
Material to procurement spec FF-N-836; Fed Std 66; QQ-S-763.
Passivated to QQ-P-35.
Dimensions, proof load, hardness, threads to MS specs, procurement spec FF-N-836; Fed Std H28/2; Fed Std H28/20 system 21; ANSI B18.2.2.
Magnetic permeability to procurement spec FF-N-836.
Quality assurance to procurement spec FF-N-836; Mil Std 105.