Cap Head Screw

8.8 allen cap head screw

Class 8.8 hardened Allen bolts are made from medium carbon steel and undergo heat treatment to achieve a tensile strength of 800 MPa and a yield strength of 640 MPa. These bolts are typically manufactured according to DIN 912 or ISO 4762 standards and are available in diameters from 4 to 24 millimeters and lengths from 10 to 200 millimeters. The head is designed with an internal hexagon and a 90-degree angle. Surface finishes may include plain, phosphate-coated, cold-galvanized, or black oxide for improved corrosion resistance. This type of bolt is well-suited for structural and mechanical joints that require medium to high strength.

The thread of a class 8.8 Allen bolt is metric and designed according to ISO standards, with pitch values ranging from 0.7 to 2.5 millimeters. Machining precision is maintained within a ±0.15 millimeter tolerance. After heat treatment, the surface hardness ranges between 22 and 32 HRC. These bolts provide stable performance under moderate torque and high tensile loads. They are widely used in automotive, structural steel, industrial machinery, and heavy equipment applications. Allen bolts of this grade are fastened with a hex key, ensuring a secure and durable connection.

galvanized cap head screw

Galvanized Allen bolts are typically made from carbon steel grades 8.8 and 10.9, with tensile strength ranging from 800 to 1040 MPa. These bolts have diameters between 4 and 24 millimeters and lengths ranging from 10 to 200 millimeters. They are manufactured according to DIN 912 and ISO 4762 standards and feature an internal hexagonal head with a 90-degree angle. Cold or hot-dip galvanizing increases resistance to corrosion and rust in humid and industrial environments. The coating thickness ranges from 5 to 25 microns, providing long-term protection against oxidation.

The threading of galvanized Allen bolts is produced to DIN and ISO standards with a dimensional tolerance of ±0.15 millimeters. Thread pitch usually ranges from 0.7 to 2.5 millimeters and is available in both full-thread and half-thread variants. Surface hardness after heat treatment and galvanizing reaches 35 to 45 HRC, improving wear resistance and preventing plastic deformation. These bolts are widely used in construction, automotive, and industrial machinery due to their high strength and long-lasting durability, making them ideal for high-stress connections.

8X40 stainless steel cap head screw

The Allen bolt A2 cylindrical head with size M8 and length 40 mm is manufactured from stainless steel grade A2-70, offering a tensile strength of about 700 MPa. Its approximate weight is 15 grams, and due to its 8 mm diameter and 40 mm length, it is commonly used in medium to heavy industrial joints. The thread is designed according to ISO 4762 with a 1.25 mm pitch, ensuring uniform load distribution along the threads.

In terms of corrosion resistance, the A2 Allen bolt performs well in humid and semi-corrosive environments thanks to chromium and nickel content in the alloy. It is produced in compliance with DIN 912 or ISO 4762 standards and is suitable for applications in oil and gas industries, food processing, and mechanical machinery. Stainless steel A2 naturally resists rusting, eliminating the need for additional coatings, which significantly increases the service life of the connection.

Class 8 cap head screw

Dry Allen screws are produced in three general shapes: cylindrical head, flat head, and allen nut. The most widely used type of dry Allen screw is the cylindrical head type, which is produced according to the DIN912 standard. Class 8.8 dry allen screw with a cylindrical head, according to the standard, should be produced as a half rib with coarse ribs, but sometimes full rib examples of these screws are also produced to meet the needs of the market.