Ratchet Wrench 1/4"

The 1/4" drive ratchet is the smallest of our three ratchets and the one a working shop reaches for when the fastener is small enough that the 3/8" or 1/2" ratchet would be oversized. Bit-socket work (hex and Torx bits on a 1/4" socket carrier), shifter adjustment screws on a 1/4" extension, small accessory hardware, and any close-quarters fastener where the larger ratchet's body wouldn't fit.

The 1/4" Ratchet Wrench (Unior 188.1/1ABI-US) has 40 teeth and a 9° working angle. The 3/8" and 1/2" ratchets run 75 teeth at 4.8°, so each click of the 1/4" swings nearly twice as far; bit-socket work usually has enough swing room to accommodate.

The 157 mm overall length keeps leverage modest, which suits a 1/4" drive: long-handle leverage on a small drive size will twist the drive square under high torque, and the short body keeps the operator from overloading it. For higher-torque work, step up to the 3/8" or 1/2" ratchet.

What the 1/4" handles

• Bit-socket work with Unior's hex bits and Torx bits
• Shifter and brake-lever adjustment screws
• Small accessory hardware (cyclo-computer mounts, frame protectors, cable guides)
• Disc-brake adapter mounting bolts at hand-torque (final torque should be done with a torque wrench)

Specs

• 1/4" square drive, made to ISO 3315
• 40 teeth, 9° working angle, with a push-button safety lock that holds the socket until released
• 157 mm overall length
• Drop-forged premium flex chrome vanadium steel body, hardened and tempered, 111 g
• Trivalent chrome plated to ISO 1456:2009
• Double-component handle
• Article number: 188.1/1ABI-US (the 1/4" member of the family; 3/8" is 238.1/1ABI-US, 1/2" is 190.1/1ABI-US)

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. Unior publishes the same construction for all three of its bike-program ratchets: a drop-forged, hardened and tempered premium flex chrome vanadium steel body, trivalent chrome plated to ISO 1456:2009, on a heavy-duty double-component handle. The 188.1/1ABI-US is that build sized for the 1/4" square drive, and it carries Unior's lifetime warranty.

Pro tip from our mechanics

The 1/4" ratchet's most common misuse is reaching for it when the work actually needs the 3/8". A 1/4" drive socket on a tight fastener will twist or strip the drive square before the fastener moves. Choose the drive size for the fastener, not for the convenience of the handle already in your hand. Our workshop hand tools guide covers ratchet selection and the rest of the workshop tool layer: Workshop hand tools every bike shop needs →

FAQ

What drive size is this ratchet, and what fits on it? It is a 1/4-inch square drive (Unior 188.1/1ABI-US), made to ISO 3315. Any 1/4-inch drive socket or bit socket mounts on it, including our 187/2HX hex bit sockets, 187/2TX Torx bit sockets and the 188H6P12 socket rail. With the 238.7/1 adapter it will also turn 3/8-inch sockets at hand torque.

How many teeth does it have, and how far does the handle swing per click? The mechanism has 40 teeth, so each click advances 9 degrees. The 3/8-inch 238.1/1ABI-US and 1/2-inch 190.1/1ABI-US use 75 teeth and a 4.8-degree working angle, so the 1/4-inch ratchet needs a little more arc in tight spots.

How do I reverse the direction and release a socket? The lever on the head switches the drive direction. A safety lock holds the socket on the square drive, and pressing the button on the head releases it, so sockets cannot work loose on the bench and come off when you want them to.

How big is it, and can it be serviced? It measures 157 mm overall and weighs 111 g, with a 24.5 by 25 mm head. Unior lists a spare-parts set for the mechanism (188.11, shared with the 188.1/1FBI flex-head version); it is not currently listed on uniorusa.com. The tool carries Unior's lifetime warranty against defects in manufacturing or materials.