Screwdrivers & Fastener Drives
Slotted, Phillips, hex, Torx and other drive systems that shaped shop kits.
Why did XZN triple-square fasteners spread with European cars?
Short answer: XZN or triple-square fasteners have twelve points in a square-shaped pattern.
XZN or triple-square fasteners have twelve points in a square-shaped pattern. They spread on German vehicles for driveshafts, axles and other components, and shops adopted XZN bit sets.
Why have stubby screwdrivers long been useful in car work?
Short answer: Stubby screwdrivers have short shanks and handles for use in confined spaces.
Stubby screwdrivers have short shanks and handles for use in confined spaces. They have long been used in automotive work where full-length drivers do not fit.
Why were screw starter screwdrivers useful on older vehicles?
Short answer: Screw starters hold a screw on the blade using clips or a split blade so it can be started in hard-to-reach spots.
Screw starters hold a screw on the blade using clips or a split blade so it can be started in hard-to-reach spots. They were especially useful on older vehicles with carburetors and distributors.
Why did magnetic screwdriver tips become common?
Short answer: Magnetized tips hold steel screws on the bit, making them easier to start.
Magnetized tips hold steel screws on the bit, making them easier to start. They became common as technicians worked in tighter engine bays where dropped screws are hard to retrieve.
Why did thread chasers become recommended over taps for cleaning threads?
Short answer: Thread chasers clean and restore existing threads without cutting new material.
Thread chasers clean and restore existing threads without cutting new material. They became recommended for cleaning block bolt holes because cutting taps can remove metal and weaken threads.
Why did shops need both SAE and metric tap and die sets?
Short answer: Tap and die sets cut internal and external threads to repair damaged bolts, studs and holes.
Tap and die sets cut internal and external threads to repair damaged bolts, studs and holes. As vehicles used both SAE and metric fasteners during the late twentieth century, shops needed complete sets in both systems.
When did helical thread repair inserts become common in engine repair?
Short answer: Helical coiled-wire inserts restore damaged threaded holes by drilling, tapping and installing a new thread.
Helical coiled-wire inserts restore damaged threaded holes by drilling, tapping and installing a new thread. They became widely used in engine and transmission repair as aluminum components with easily stripped threads became common.
How long have screw extractors been used to remove broken bolts?
Short answer: Tapered, reverse-spiral screw extractors have long been used to remove broken bolts by biting into a hole drilled in the fastener.
Tapered, reverse-spiral screw extractors have long been used to remove broken bolts by biting into a hole drilled in the fastener. Because hardened extractors can snap off inside the bolt, many shops later favored left-hand drill bits, welding a nut onto the stub or specialty extraction kits. Follow the equipment maker's safety instructions when using it.
Why did vehicle assembly move toward fewer fastener types?
Short answer: Manufacturers have tried to standardize fastener drives on assembly lines to reduce tooling costs and errors.
Manufacturers have tried to standardize fastener drives on assembly lines to reduce tooling costs and errors. However, vehicles still use many types of fasteners, so technicians maintain a broad range of drivers, bits and sockets.
When did bolt grade markings become standard?
Short answer: Bolt grade markings indicate strength classes.
Bolt grade markings indicate strength classes. Head markings for SAE grades and metric property classes became standard ways to identify bolt strength, helping prevent use of weaker bolts in critical applications.
Why did automakers adopt torque-to-yield bolts?
Short answer: Torque-to-yield bolts are tightened into their yield range to achieve more consistent clamping force.
Torque-to-yield bolts are tightened into their yield range to achieve more consistent clamping force. Automakers adopted them in the late twentieth century for cylinder heads, connecting rods and other critical joints, and they are typically meant to be replaced rather than reused.
Why did automakers adopt metric fasteners?
Short answer: Metric fasteners are part of the global standard system used in most countries.
Metric fasteners are part of the global standard system used in most countries. As automakers globalized production and design during the 1970s and 1980s, U.S. manufacturers increasingly adopted metric fasteners to simplify international sourcing and manufacturing.
Why did thread pitch gauges become essential in mixed SAE and metric shops?
Short answer: Thread pitch gauges identify threads per inch or millimeter pitch by matching toothed blades to a fastener.
Thread pitch gauges identify threads per inch or millimeter pitch by matching toothed blades to a fastener. They became essential as shops worked on both SAE and metric vehicles during the metric transition.
When were ratcheting screwdrivers popular?
Short answer: Ratcheting and spiral-ratchet "Yankee" screwdrivers were popular in the early twentieth century, letting the handle turn the bit one way and freewheel the other.
Ratcheting and spiral-ratchet "Yankee" screwdrivers were popular in the early twentieth century, letting the handle turn the bit one way and freewheel the other. Modern ratcheting bit drivers carry on the idea.
Who made the Yankee screwdriver?
Short answer: The Yankee spiral ratcheting screwdriver was made by North Brothers of Philadelphia and later by Stanley.
The Yankee spiral ratcheting screwdriver was made by North Brothers of Philadelphia and later by Stanley. It turned the bit when the handle was pushed and was popular with carpenters and mechanics before cordless drivers.
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.