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List of screw drives

The meaning of «list of screw drives»

At a minimum, a screw drive is a set of shaped cavities and protrusions on the screw head that allows torque to be applied to it.[1][2] Usually, it also involves a mating tool, such as a screwdriver, that is used to turn it. The following heads are categorized based on frequency,[citation needed] with some of the less-common drives being classified as “tamper-resistant.”

Most heads come in a range of sizes, typically distinguished by a number, such as "Phillips #00". These sizes do not necessarily describe a particular dimension of the drive shape, but rather are arbitrary designations.

Slot screw drives have a single horizontal indentation (the slot) in the fastener head and is driven by a "common blade" or flat-bladed screwdriver. This form was the first type of screw drive to be developed, and for centuries, it was the simplest and cheapest to make. Additionally, it is unique compared to other common drives, due to it being straightforward to manufacture the slot head, and the ability to be driven by a simple handtool. The slotted screw is commonly found in existing products and installations, along with use in simple carpentry work and in applications where minimal torque is needed. Slot screws are also used in the restoration of antique furniture, vehicles, and equipment.

However, this design is not well-suited for installation by power tools, given that a power driver often slips out of the slot; this often causes damage to the screw and surrounding material. For this reason, cruciform-slotted along with drives have replaced the slot drive in numerous applications. The tool used to drive a slot is called a common blade, flat-blade, slot-head, flat-tip[3] or flat-head / flathead[5] screwdriver. A hollow-ground screwdriver is less likely to cam out (leave the slot due to the torque being translated into an axial force, similar to that encountered with Phillips drive but dependent only on driver blade), so more torque can be applied without damaging the screw head. Flat-blade jeweler's screwdrivers and the tips found in .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}1⁄4-inch or 6.4-millimeter drive sets are generally hollow-ground. Note that it is this typical chisel shape which allows 9 screwdriver sizes to drive 24 different slotted screw sizes, with the drawbacks of not fitting as closely as a hollow-ground screwdriver would, and increasing the possibility of damaging the fastener or surrounding area.

ISO 2380-1[4] specifies the internationally standardized shape and dimensions of the tips of screwdrivers for slotted-head screws as well as the minimum test torque the blade-to-handle connection shall withstand. Screwdriver tips are generally designated by blade thickness × width in mm, e.g. 1.2 × 6.5 which roughly matches a classic North American 1/4" screwdriver although the North American one is often a bit thinner (~1.0 mm).

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