List of screw drives(螺丝刀型号)/附PHILLIP 螺丝头规格
A screw drive is the system ud to turn a screw .[1] At a minimum, it is a feature on the screw that allows for it to be turned. Usually it also involves a mating tool , such as a screwdriver , that is ud to turn it. The following heads are categorized bad on commonality, with the less common drives being classified as "tamper-resistant". Most heads come in a range of sizes.
[edit ]Common types [edit ]External types
All of the screw drives are characterized by a female tool and a male fastener.
[edit ]Square
A square screw drive us square shaped fastener heads. They can be turned with a crescent -type wrench, open-end wrench , or 8- or 12-point [2] sockets . Extremely common in the 19th and early 20th centuries. Less common today becau the hex has largely displaced it. It is still widely ud on theatrical lighting equipment.
[edit ]Hex
A hex screw drive us six-sided fastener heads. The fastener is known as a hex head cap screw . They can be turned with a crescent-type wrench, combination wrench , or 6 and 12-point sockets. Better than square for locations where surrounding obstacles limit wrenching access, becau smaller wrench-swing arcs can be successful.
[edit ]Pentagon
A pentagon screw drive us five-sided fastener heads. The fastener is known as a penta screw . They require a special five-point socket in order to be turned. Water meter covers, natural gas valves, and electrical cabinets are commonly cured with penta fasteners. It is also common in the U.S. for fire hydrants to have valves with a pentagon drive.
[edit ]Slotted types [edit ]Slot
Slot drive tool and fastener sizes [3]Blade width
Fastener size
3⁄
32
in (2.4 mm) 0–1 1
⁄8 in (3.2 mm)
2
The slot screw drive has a single slot in the fastener head and is driven by a flat-bladed screwdriver. The slotted screw is common in woodworking applications, but is not often en in applications where a power tool would be ud becau a power driver tends to slip out of the head and potentially damage the surrounding material. The tool ud to drive a slot is called a slot-head , flat-tip ,[3] or flat head .[4]
[edit ]Cross
A cross screw drive has two slots, oriented perpendicular to each other, in the fastener
香蕉炖冰糖head; a slotted screwdriver is still ud to drive just one of the slots. This type is usually found in cheaply made roofing bolts and the like, where a thread of 5 mm (0.20 in) or above has a large flattened pan head . The sole advantage is that they provide some measure of redundancy: should one slot be chewed up in rvice, the cond may still be ud.
[edit ]Cruciform types
See also: cross-slotted , Torq-t , and Phillips/square
The following are screw drives bad on a cruciform shape, i.e. a cross shape. Other names for the types of drives are cross-head and cross-point .
[edit ]Phillips
Created by Henry F. Phillips , the Phillips screw drive was purpoly designed to cam out when the screw stalled, to prevent the fastener damaging the work or the head, instead damaging the driver. This was caud by the relative difficulty in building torque limiting into the early drivers.
The American Screw Company was responsible for devising a means of manufacturing the screw, and successfully patented and licend their method; other screw makers of the 1930s dismisd the Phillips concept becau it calls for
a relatively complex recesd socket shape in the head of the screw — as distinct from the simple milled slot of a slotted type screw.
There are five relatively common (and two rather uncommon) Phillips drive sizes that are different from the screw size; they are designated 000, 00, 0, 1, 2, 3, and 4 (increasing in size).[3][5]
[edit ]Frearson
5⁄32 in (4.0 mm) 3 3⁄16 in (4.8 mm) 4–5 1⁄4 in (6.4 mm) 6–7 5⁄16 in (7.9 mm) 8–10 3⁄8 in (9.5 mm) 12–14 7⁄16 in (11 mm) 16–18 1什么是网络营销
⁄2 in (13 mm)
18–24
Phillips drive tool and fastener sizes [3]
Tool size Fastener size
0 0–1 1 2–4 2 5–9 3 10–16 4
18–24
半个月亮打一字谜The Frearson screw drive, also known as the Reed and Prince screw drive, is similar to a Phillips but
has a more pointed 75° V shape.[6] Its advantage over the Phillips drive is that one driver or bit fits all screw sizes. It is found mainly in marine hardware and requires a special screw driver or bit to work properly. The tool recess is a perfect cross, unlike the Phillips head, which is designed to cam out. It was developed by an English inventor named Frearson in the 19th century and produced from the late 1930s to the mid-1970s by the former Reed & Prince Manufacturing Company of Worcester, Massachutts.
[edit]French recess
French recess driver bit
This ction requires expansion.
Also called BNAE NFL22-070 after its Bureau de Normalisation de l'Aéronautique et de l'Espace standard number. [edit]JIS B 1012
The JIS B 1012 is commonly found in Japane equipment. It looks like a Phillips screw, but is desig
ned not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight. Heads are usually identifiable by a single dot to one side of the cross slot.
[edit]Mortorq
The Mortorq drive, developed by the Phillips Screw Company, is a format ud in automotive and aerospace applications. It is designed to be a lightweight, low-profile and high-strength drive, with full contact over the entire recess wing reducing risk of stripping.[7]
[edit]Pozidriv
Screws with the Pozidriv head.
The Pozidriv, sometimes misspelled Pozidrive, screw drive is an improved version of the Phillips screw drive. It is jointly patented by the Phillips Screw Company and American Screw Company. The name is thought to be an abbreviation
of pos itive driv e. Its advantage over Phillips drives is its decread likelihood to cam out, which allows greater torque to be applied.[8][9][10] In ANSI standards it is referred to as type IA.[11] It is very similar to, and esntially compatible with, the Supadriv screw drive.[12]
Phillips drivers have an intentional angle on the flanks and rounded corners so they will cam out of the slot before a power tool will twist off the screw head. The Pozidriv screws and drivers have straight sided flanks.
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The Pozidriv screwdriver and screws are also visually distinguishable from Phillips by the cond t of cross-like features t 45 degrees from the cross. The manufacturing process for Pozidriv screwdrivers is slightly more complex. The Phillips driver has four simple slots cut out of it, whereas in the Pozidriv each slot is the result of two machining process at right angles. The result of this is that the arms of the cross are parallel-sided with the Pozidriv, and tapered with the Phillips.意思相近的成语
This design is intended to decrea the likelihood that the Pozidriv screwdriver will slip out, provide a greater driving surface, and decrea wear.[8] The chief disadvantage of Pozidriv screws is that they are visually quite similar to Phillips, thus many people are unaware of the difference or do not own the correct drivers for them, and u incorrect screwdrivers. This results in difficulty with removing the screw and damage to the slot, rendering any subquent u of a correct screwdriver unsatisfactory. Phillips screwdrivers will fit in and turn Pozidriv screws, but will cam out if enough torque is applied, potentially damaging the screw head. The marker lines on a Pozidriv screwdriver will not fit a Phillips screw correctly, and are likely to slip or tear out the screw head.
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[edit]Supadriv
The Supadriv (sometimes found incorrectly as "Supadrive") screw drive is very similar in function and appearance to Pozidriv—indeed, the two are often thought to be identical—and is a later development by the same company. The description of the Pozidriv head applies also to Supadriv. While each has its own driver,[13] the same screwdriver heads may be ud for both types without damage; for most purpos it is unnecessary to distinguish between the two drives. Pozidriv and Su
padriv screws are slightly different in detail; the later Supadriv allows a small angular offt between the screw and the screwdriver, while Pozidriv has to be directly in line.[12][14]
In detail, the Supadriv screwhead is similar to Pozidriv but has only two identification ticks, and the condary blades are larger. Drive blades are about equal thickness. The main practical difference is in driving screws into vertical surfaces: that clo to a near vertical surface to drive the screws into the drivers, Supadriv has superior bite, making screwdriving more efficient, with less cam out.[13]
[edit]Robertson
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Clo-up of a Robertson screw
A Robertson, also known as a square,[15] screw drive has a square-shaped socket in the screw head and a square protrusion on the tool. Both the tool and the socket have a taper to make inrting the tool easier. Robertson screws are ud mainly in Canada (where they are very common), though they can be found elwhere.[16] Robertson screwdrivers are easy to u one-handed, becau the tapered socket retains the screw, even if it is shaken. They also allow for the u of angled screw drivers and trim head screws. The socket-headed Robertson screws are lf-centering, reduce cam out, stop a power tool when t, and can be removed if painted-over or old and rusty. In industry, they speed up production and reduce product damage.[17]
Canadian P.L. Robertson invented the Robertson screw and screwdriver in 1908 and received a patent in 1909. An earlier square drive wood screw patent, U.S. Patent 161,390, was issued to Allan Cummings on March 30, 1875.自称臣是酒中仙
Robertson had licend the screw in England, but the party that he was dealing with intentionally drove the company into bankruptcy and purchad the rights from the trustee, thus circumventing Robertson.[citation needed] He spent a small fortune buying back the rights. Subquently, he refud to allow anyone to make the screws under licen. When Henry Ford tried
