Socket Head Cap Screws are ideal when space is limited with easy access to the drive along with the highest strength rating of most fasteners. The top of the cylindrical head on a socket head cap screw is flat and chamfered the side may be plain or knurled and the bearing surface is flat. Use a hex key also called an Allen wrench or hex power bit to drive a socket screw Also known as: Socket Head Allen Bolts Socket Hex Cap Screws Cap Screws Allen Bolt Socket Screws SHCS Material / Coating: Marine Grade Stainless Steel A4-70 G316 is the ultimate corrosion resistance fastener. Designed to be used in all conditions. The best fastener for marine coastal chemical and food environments. Stainless steels are largely non-magnetic but it is common for stainless steel fasteners to show a small degree of magnetism which is a result of work-hardening during the manufacturing process Can Stainless corrode?: Stainless steel is corrosion-resistant but not corrosion-proof and corrosion can occur if the material is installed or handled incorrectly. The use of tools and drills made from conventional steel during the installation of stainless steel fasteners may also lead to problems. Even the hardest of tools can produce debris that leaves minute steel particles on the stainless steel fastener surfaces or in pre-drilled holes. It is these particles that often rust when exposed to moisture or oxygen and can result in a stained or tarnished finish to the stainless steel material Galling: can occur when excessive pressure is used to tighten a nut onto a thread common with stainless fasteners but can also be an issue with other materials. Fasteners with damaged or fine threads are particularly prone to galling. Some suggestions to help prevent thread galling: Tightening the nut more slowly without excessive pressure will frequently reduce or sometimes solve completely the problem. As the installation RPM speed increases the heat generated with friction during tightening escalates the chances of thread galling. Reduce the friction by applying a suitable lubricant to the thread frequently eliminates thread galling. Typical lubricants are chloride-paraffine molykoat lacquer molybdenum disulphide high pressure oil graphite mica or talc some assemblies where there is extreme pressure corrosion resistant grease or waxes may also be effective Thread Pitch (Metric): is the distance between the peaks of two threads along a screw bolt nut or fastener expressed in millimetres (mm). Used when referring to Metric parts. For example a thread pitch of 1.50mm means that the distance between one thread and the next is 1.50mm Fastener Length: is generally measured from the point where the surface of the material will be when the fastener is installed to the end of the fastener. Thus fasteners with heads that sit above the surface are measured from under the head to the end of the fastener while fasteners that sit flush with the surface are measured from the top of the head to the end of the fastener Measurements: Thread Lengths have been included as a guide only. Due to stock being sourced from multiple suppliers variations do exist.