TECHNICAL SPECIFICATION The ASTM standard covers alloy steel and stainless steel bolting materials for high and low temperature service. This specification includes fasteners intended for use in pressure vessels, valves, flanges, and fittings. Range: 12 mm dia to 72 mm dia Grade: A193 Grade B7 | Nuts A194 Grade 2H A193 Grade B7M | Nuts A194 Grade 2HM A193 Grade B16 | Nuts A194 Grade 4 A320 Grade L7 | Nuts A194 Grade 2H A320 Grade L7M | Nuts A194 Grade 2HM A325 Bolts, Nuts & Washer