Post by containerhome on May 3, 2016 1:00:57 GMT -5
Wood Screw: These are threaded along their entire length and are typically used to secure a shaft from rotating. They're used in pulleys, sprockets, collars and knobs among other things.
Phillips drive tool and fastener sizesTool sizeFastener size
The Phillips screw drive was created by John P. Thompson, who after failing to interest manufacturers, sold his design to businessman Henry F. Phillips.[7][8] Phillips is credited with forming a company (Phillips Screw Company), improving the design, and promoting the adoption of his product.The original patent[9] expired in 1966, but the Phillips Screw Company continued to develop improved designs.
The American Screw Company of Providence, Rhode Island was responsible for devising a means of efficiently manufacturing the screw, and successfully patented and licensed their method; other screw makers of the 1930s dismissed the Phillips concept because it called for a relatively complex recessed socket shape in the head of the screw — as distinct from the simple milled slot of a slotted type screw. The Phillips screw design was developed as a direct solution to a number of problems with slotted screws: easy cam out, precise alignment required to avoid cam out and damage, and difficulty of driving with powered tools.
Phillips drive bits are often designated by the letters "PH", plus a size code 0000, 000, 00, 0, 1, 2, 3, or 4 (by order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.
The design is often criticized for its tendency to cam out at lower torque levels than other "cross head" designs. There has long been a popular belief that this was actually a deliberate feature of the design, for the purpose of assembling aluminum aircraft without overtightening the fasteners. Evidence is lacking for this specific narrative and the feature is not mentioned in the original patents.However, a subsequent refinement to the original design described in US Patent #2,474,994describes this feature.
The Frearson screw drive, also known as the Reed and Prince screw drive, is similar to a Phillips but the Frearson has a sharp tip and larger angle in the V shape.[16] One advantage over the Phillips drive is that one driver or bit fits all screw sizes. It is often found in marine hardware and requires a Frearson screwdriver or bit to work properly. The tool recess is a perfect, sharp cross, allowing for higher applied torque, unlike the rounded, tapered Phillips head, which can cam out at high torque. It was developed by an English inventor named Frearson in the 19th century and produced from the late 1930s to the mid-1970s. The Reed & Prince Mfg. Company of Worcester, Massachusetts, was put into bankruptcy in 1987 and liquidated in 1990. Another entity called Reed & Prince Manufacturing Corporation, now of Leominster, Massachusetts, purchased some of the assets including the name at the liquidation sale.
The Pozidriv (sometimes purposely misspelled Pozidrive to avoid trademark infringement) screw drive is an improved version of the Phillips screw drive. Pozidriv was jointly patented by the Phillips Screw Company and American Screw Company. The name is thought to be a portmanteau of the words "positive" and "drive." Its advantage over Phillips drives is its decreased likelihood to cam out, which allows greater torque to be applied.In ANSI standards, it is referred to as "Type IA." It is very similar to, and essentially compatible with, the Supadriv screw drive.
Pozidriv drive Wood Screws are often designated by the letters "PZ" plus a size code of 0, 1, 2, 3, 4 or 5 (by order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.If you want to know more,please click www.din571.com
Phillips drive tool and fastener sizesTool sizeFastener size
The Phillips screw drive was created by John P. Thompson, who after failing to interest manufacturers, sold his design to businessman Henry F. Phillips.[7][8] Phillips is credited with forming a company (Phillips Screw Company), improving the design, and promoting the adoption of his product.The original patent[9] expired in 1966, but the Phillips Screw Company continued to develop improved designs.
The American Screw Company of Providence, Rhode Island was responsible for devising a means of efficiently manufacturing the screw, and successfully patented and licensed their method; other screw makers of the 1930s dismissed the Phillips concept because it called for a relatively complex recessed socket shape in the head of the screw — as distinct from the simple milled slot of a slotted type screw. The Phillips screw design was developed as a direct solution to a number of problems with slotted screws: easy cam out, precise alignment required to avoid cam out and damage, and difficulty of driving with powered tools.
Phillips drive bits are often designated by the letters "PH", plus a size code 0000, 000, 00, 0, 1, 2, 3, or 4 (by order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.
The design is often criticized for its tendency to cam out at lower torque levels than other "cross head" designs. There has long been a popular belief that this was actually a deliberate feature of the design, for the purpose of assembling aluminum aircraft without overtightening the fasteners. Evidence is lacking for this specific narrative and the feature is not mentioned in the original patents.However, a subsequent refinement to the original design described in US Patent #2,474,994describes this feature.
The Frearson screw drive, also known as the Reed and Prince screw drive, is similar to a Phillips but the Frearson has a sharp tip and larger angle in the V shape.[16] One advantage over the Phillips drive is that one driver or bit fits all screw sizes. It is often found in marine hardware and requires a Frearson screwdriver or bit to work properly. The tool recess is a perfect, sharp cross, allowing for higher applied torque, unlike the rounded, tapered Phillips head, which can cam out at high torque. It was developed by an English inventor named Frearson in the 19th century and produced from the late 1930s to the mid-1970s. The Reed & Prince Mfg. Company of Worcester, Massachusetts, was put into bankruptcy in 1987 and liquidated in 1990. Another entity called Reed & Prince Manufacturing Corporation, now of Leominster, Massachusetts, purchased some of the assets including the name at the liquidation sale.
The Pozidriv (sometimes purposely misspelled Pozidrive to avoid trademark infringement) screw drive is an improved version of the Phillips screw drive. Pozidriv was jointly patented by the Phillips Screw Company and American Screw Company. The name is thought to be a portmanteau of the words "positive" and "drive." Its advantage over Phillips drives is its decreased likelihood to cam out, which allows greater torque to be applied.In ANSI standards, it is referred to as "Type IA." It is very similar to, and essentially compatible with, the Supadriv screw drive.
Pozidriv drive Wood Screws are often designated by the letters "PZ" plus a size code of 0, 1, 2, 3, 4 or 5 (by order of increasing size); the numerical bit size codes do not necessarily correspond to nominal screw size numbers.If you want to know more,please click www.din571.com