Ratchet Wrench 3/8"

The 3/8" drive ratchet is the middle size of Unior's three bike-program ratchets, between the 1/4" and the 1/2". It turns 3/8" drive sockets and hex bit sockets, such as the 236/2HX hex bit sockets in 4, 5, 6, 8 and 10 mm and the 3/8" pieces in the 1782 Bits and Sockets Set. One thing to know before you buy: Unior's bottom bracket sockets, cassette lockring tools and suspension top-cap sockets are built around a 1/2" square, so they need a 1/2" drive or a step-up adaptor. Those jobs belong to the 1/2" ratchet.

The 3/8" Ratchet Wrench (Unior 238.1/1ABI-US) has 75 teeth and a 4.8° working angle. The 4.8° matters in close quarters: where you can only swing the handle 10° at a time, the 75-tooth mechanism clicks twice per swing, while a 40-tooth ratchet such as Unior's 1/4" needs 9° for every click. A safety lock holds the socket on the square until you press the release button on the head.

The body is drop-forged premium flex chrome vanadium steel, hardened and tempered, then trivalent chrome plated, and it carries a double-component handle. At 200 mm overall and 239 g it sits between the 157 mm 1/4" ratchet and the 260 mm 1/2"; for jobs that need heavier leverage (pedal removal at full breakaway torque), the 1/2" version is the right choice.

What the 3/8" handles

• Hex nuts and bolt heads, with 3/8" drive 6-point sockets such as the 15 mm socket in the 1782 set
• Socket-head hex bolts, with 3/8" hex bit sockets: the 236/2HX range runs 4, 5, 6, 8 and 10 mm, and the long-type 236/2HXL reaches recessed bolts
• Not Unior's 1/2"-drive bike sockets, which need a 1/2" drive (bottom bracket sockets, cassette lockring tools and the aluminum-anodized top cap socket)
• 1/4" drive sockets and bits, through the 238.7/1 adapter (3/8" ratchet to 1/4" socket), which also comes in the 1782 set

For smaller fasteners and bit-socket work, switch to the 1/4" ratchet. For heavier-torque work and Unior's 1/2"-drive bike sockets, the 1/2" ratchet.

Specs

• 3/8" square drive
• 75 teeth, 4.8° working angle, with a push-button safety lock that holds the socket until released
• 200 mm overall length, 30 mm thick and 35 mm wide at the head, 239 g
• Drop-forged premium flex chrome vanadium steel body, hardened and tempered, made to ISO 3315
• Trivalent chrome plated to ISO 1456:2009
• Double-component handle (hard core for torque, soft outer for grip)
• Article number: 238.1/1ABI-US (the 3/8" member of the family; 1/4" is 188.1/1ABI-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 one construction for its three bike-program ratchets: a drop-forged body in premium flex chrome vanadium steel, hardened and tempered, trivalent chrome plated to ISO 1456:2009, on a heavy-duty double-component handle. The 238.1/1ABI-US is that build sized for the 3/8" square, and it carries Unior's lifetime warranty.

Pro tip from our mechanics

The single best diagnostic for a worn ratchet: hold it in one hand and slow-spin the head in the engagement direction. A clean ratchet feels smooth; a worn one catches and skips. If the 75-tooth mechanism in the 238.1/1ABI-US ever does, it can be serviced: Unior lists a spare-parts set for it (238.11). Our workshop hand tools guide covers ratchets and the rest of the workshop tool layer: Workshop hand tools every bike shop needs →

FAQ

What can I drive with a 3/8-inch ratchet on a bike? Any 3/8-inch drive socket or hex bit socket. On uniorusa.com that covers the 236/2HX hex bit sockets (4, 5, 6, 8 and 10 mm), the long-type 236/2HXL and the 3/8-inch pieces in the 1782 Bits and Sockets Set. The 238.7/1 adapter steps the ratchet down to 1/4-inch sockets and bits.

Does it fit Unior bottom bracket sockets and cassette lockring tools? Not without a 3/8-to-1/2-inch step-up adaptor. Unior's bottom bracket sockets, cassette lockring tools and suspension top-cap sockets take a 1/2-inch drive. Use the 1/2-inch ratchet (190.1/1ABI-US) or a 1/2-inch torque wrench for those. The 190.7/2 adaptor only works the other way: it puts 3/8-inch sockets on a 1/2-inch tool.

What does the 75-tooth mechanism change in a tight spot? Each click advances 4.8 degrees, so the ratchet keeps working where the handle can only swing a few degrees. Unior's 1/4-inch ratchet (188.1/1ABI-US) has 40 teeth and needs 9 degrees per click. The 1/2-inch 190.1/1ABI-US also has 75 teeth and a 4.8-degree working angle.

How big is the 3/8-inch ratchet, and can the mechanism be serviced? It measures 200 mm overall and weighs 239 g, with a head 30 mm thick and 35 mm wide. Unior lists a spare-parts set for the mechanism (238.11); it is not currently listed on uniorusa.com. The tool carries Unior's lifetime warranty against defects in material and workmanship.