Overview

• Fillister head types have thick, cylindrical heads of a relatively small diameter
• This allows a deep drive slot on a small area for increased torque
• Machine screws without washers can be used with both flat and lock washers
• Slotted drive types are used with flat-blade drivers
• They have one linear slot that runs the length of the head
• Drivers must be centered in the slot during tightening or they will slip out and damage the fastener
• Stainless steel is a strong, corrosion-resistant alloy with excellent resistance to heat
• It is used in high-stress, outdoor and corrosive applications.