If you have ever used any hex head type of cap screws then you must be aware that they are thick, having a hexagonal head. There will also have a washer face below the head for providing a sufficient amount of bearing surface to tighten with a certain wrench. They are actually general-purpose threaded fasteners that are designed for inserting in a pre-tapped holes or using certain nuts.
Fair Wind Fasteners manufactures these solid 651 silicon type bronze hex cap screws, which are often referred also as tap bolts or hex head bolts, which are made of a solid bronze alloy, used mostly for marine purposes.
These screws are available in the following few materials:
- Alloy steel
It contains sufficient alloying elements, which are other than carbon for affecting properties like tensile strength. Usually, they are more responsive to any mechanical treatments and heat as compared to plain carbon steel.
Aluminum is a moisture and corrosion-resistant material that can be excellent for marine use. It can also provide necessary strength of any MS (Mild Steel) at almost 1/3rd of the weight. Also, aluminum is a non-magnetic metal.
Brass is another material preferred for marine use, which is an alloy of zinc and copper that can resist rust and also any moderate atmospheric corrosion. Brass may not be having highstrength,however, it is durable and also a good conductor of electricity. Also, it is nonmagnetic and often preferred for its appearance.
3. Nickel copper alloy
This is another corrosion-resistant metal alloy having excellent thermal conductivity, however, it has slightly less electrical conductivity as compared to copper. This material is quite strong and also fatigue-resistant.
4. Silicon bronze
This is again an alloy of tin and copper having higher hardness and strength than any brass with silicon diffusion done at a high temperature. It is very ductile and has a high resistance to any repeated stresses, fatigue, and corrosion.
5. Stainless steel
It contains 12% (minimum) chromium for offering exceptional resistance to any extreme environmental conditions. It has very high anticorrosive property and will never get affected by scratching, but may not be as strong ascommon alloy steels. It can be a little magnetic too.
6. 18-8 stainless steel
It contains about chromium (18%) and nickel (8%). It can offer excellent protection against corrosion and rust. This material is also preferable for marine use where salt spray or chemical fumes are present. It can be mildly magnetic material.
7. 316 Stainless Steel
It contains molybdenum (minimum of 2%) offers superior corrosion resistance inextreme environments. It is nonmagnetic and cannot be hardened or heat treated.
This isthe most common material used as a fastener material. They are available in the following types:
- Alloy steel– It contains sufficient alloying elements besides carbon to influence the fastener’s properties, it generally responds more to heat and any mechanical treatments too.
- Plain steel/carbon steel)– It contains carbon and a few residual amounts of other impurities. It can be magnetic and is malleable. It caneither be cast or wrought.