Material: Carbon steel, Alloy Steel, stainless steel SUS304, SUS316, High-Strength Steel, Brass, 20# steel, Surface treatment black zinc plating
High-Strength Grade 8 Steel Square Head Screws for automotive, Made from Grade 8 steel, these screws can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems. They are at least 25% stronger than medium-strength steel screws. Large flat sides make them easy to grip with a wrench and keep them from rotating in square holes. A zinc yellow-chromate plating provides corrosion resistance in wet environments. Grade 8 steel square head screws are marked with six radial lines. Dimensions meet ASME B18.2.1 specifications. Length is measured from under the head.Variety Optimization of Automotive Fasteners:
Screws: Screws can be internally driven and come in various forms such as internal hexagon, cross-slotted, and internal hexagon with flange. Common screw head types include round head, cylindrical head with flange, flat round head, flat round head with flange, pan head, pan head with flange, countersunk head, and semi-countersunk head.
Due to the increasing demand for assembly efficiency, priority is given to the use of screws with internal hexagon and flange. The use of internal hexagon screws and cross-slotted screws is gradually being restricted as standard structures are optimized.
1. Medium-Strength Grade 5 Steel Square Head Screws, Made from Grade 5 steel, these screws are suitable for fastening most machinery and equipment. Large flat sides make them easy to grip with a wrench and keep them from rotating in square holes. A zinc yellow-chromate plating provides corrosion resistance in wet environments. Grade 5 steel square head screws are marked with three radial lines. The material meets SAE J429 specifications for quality. Dimensions meet ASME B18.2.1 specifications. Length is measured from under the head.2.Low-Strength Grade A Steel Square Head Screws, About half the strength of medium-strength screws, these screws can be used for light-duty fastening applications, such as securing access panels. Large flat sides make them easy to grip with a wrench and keep them from rotating in square holes. The material meets ASTM A307 specifications for quality. Length is measured from under the head.
