Thumb screws are designed to easily turn with one hand making them ideal to use on parts that are frequently opened and moved, such as with access panels. There are a variety of head styles including spade, knurled, round and wing. When determining the size needed for your application, please keep in mind that the length is measured from under the head to the tip of the screw.
Spade Head Thumb Screws
Spade head thumb screws, also known as spade head screws, are fully threaded and available without (plain) or with a shoulder. A shoulder pattern thumb screw allows the head of the screw to sit flush against the mating surface and helps to avoid over tightening, resulting in stripped threads. When determining the proper size needed for your application, keep in mind that length is measured from under the head. Spade head thumb screws are most commonly supplied in either steel or stainless steel, however they can also come in brass, aluminum, and a variety of other exotic metals and plastics.
Knurled Head Thumb Screws
Knurled thumb screws have a diamond, or knurled, slip-resistant screw head that is designed for controlled adjustment. Shoulder pattern thumb screws can have a straight shoulder or flared shoulder, which can also be called a washer face. All screws are fully threaded unless otherwise noted, and length is measured from under the head. Knurled thumb screws are commonly supplied in steel, stainless steel, brass, aluminum, and a variety of other exotic metals and plastics.
Thumb Screw Materials
- Stainless steel thumb screws provide corrosion protection and may be mildly magnetic.
- Steel thumb screws are often supplied with a plating or finish such as zinc, which adds protection in dry indoor applications, or black oxide, which adds a dark color but no additional protection.
- Brass thumb screws is usually selected because of its decorative properties, however it’s also an excellent conductor of electricity and nonmagnetic.
- Aluminum thumb screws are nonmagnetic and usually 1/3 the weight of steel.
- Plastic thumb screws are nonconductive and provide an excellent option when needing a lightweight material.
As a supplier of knurled and spade thumb screws, AFT offers a large selection of screw sizes and materials. Captive panel screws and knurled knobs can be used as an alternative in many applications. Please search our selection or contact our experienced sales team with any questions.