Adjustable screw for NEW (2022) clamp 1693.1 and 1693.1S (round clamp profile)

The 1693.23 is the adjustable screw for Unior's Pro repair clamps: the threaded spindle assembly that sets how far the jaws open and how hard they close on a frame tube. Unior lists it as the replacement adjuster for both current clamp heads, the auto-adjustable 1693.1 and the manually adjustable 1693.1S. On the manual clamp it is the screw you turn at every tube-diameter change, so when the threads stop holding a setting, or the spindle picks up a bend from an overtorqued handle, a new screw puts the clamp back to spec without replacing the whole head.

This is the newer of the two adjustable screws Unior makes for these clamps. From mid-2022 the 1693.1 and 1693.1S moved to round-style clamping jaws, 50 mm tall, and the adjustable screw changed with the jaws. Unior lists this version, code 629253, for the round-jaw clamps only.

Compatibility

The 1693.23 fits the round-jaw generation of both Pro repair clamp heads:

• Pro Repair Clamp, Auto Adjustable 1693.1, round-style jaws, mid-2022 onward
• Pro Repair Clamp, Manually Adjustable 1693.1S, round-style jaws, mid-2022 onward

If your clamp has the older square-style jaws, 70 mm or 90 mm tall, it takes the 1693.21 adjustable screw instead. And if the clamp on your stand is the Master Shop 1693.1M or the quick-release Pro Shop 1693.1Q, neither screw applies: those clamps use different pressure mechanisms, and the 1693.1Q has its own rebuild kit.

How to tell which screw you need

Look at the jaws, not the stand. Round-profile jaws 50 mm tall mean a mid-2022-or-later clamp and this screw, the 1693.23. Flat-faced square-style jaws at 70 mm or 90 mm mean the earlier clamp and the 1693.21. The two generations of clamp look close to identical from across a workshop, and so do the two screws, so a quick ruler check against the jaw height settles it before you order.

Specs

• Article number: 1693.23
• Unior code: 629253
• Fits: 1693.1 and 1693.1S Pro repair clamps with round-style clamping jaws (50 mm, mid-2022 onward)
• Not for: square-style jaws (70 mm or 90 mm tall; use the 1693.21) or the 1693.1M and 1693.1Q clamps
• Weight: 150 g

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The 1693.23 is that thinking applied to a wear point: the adjuster that carries the clamp's daily use is available on its own, so a hard-working clamp head stays in service instead of being replaced.

Pro tip from our mechanics

Check the jaw height before you order, even if you know when you bought the stand. Clamp heads get swapped between stands in busy workshops, and the mid-2022 changeover means two stands bought months apart can take different screws. Round jaws at 50 mm: this screw. Square jaws at 70 or 90 mm: the 1693.21. And if the clamp head itself is tired, weigh an upgrade instead of a repair: How to choose a bike repair stand →

FAQ

Which clamps does the 1693.23 adjustable screw fit? It fits Unior's Pro repair clamp heads 1693.1 (auto adjustable) and 1693.1S (manually adjustable) built from mid-2022 onward, the versions with round-style clamping jaws 50 mm tall. Unior lists it as the replacement adjuster for both models under code 629253.

How do I know whether my clamp needs the 1693.23 or the 1693.21? Check the jaws. Round-profile jaws about 50 mm tall mean a mid-2022-or-later clamp, which takes this screw, the 1693.23. Flat-faced square-style jaws 70 mm or 90 mm tall mean the earlier generation, which takes the 1693.21 instead.

Does the 1693.23 fit the Master Shop 1693.1M or Pro Shop 1693.1Q clamps? No. The 1693.1M and 1693.1Q use different pressure-setting mechanisms, so neither the 1693.23 nor the 1693.21 applies to them. The 1693.1Q has its own rebuild kit, sold separately as the 1693.1Q-SP.1.

What does the adjustable screw do on the clamp? It is the threaded spindle that sets the jaw opening and the closing pressure. On the manually adjustable 1693.1S you turn it to match the frame tube before closing the lever. A worn or bent screw is why a clamp stops holding its pressure setting, and replacing it restores the clamp without a new head.