Pop Pin M20 x 20mm Screw-In - Spring Loaded Adjustment Pin,

Pop Pin M20 x 20mm Screw-In - Spring Loaded Adjustment Pin with Lock Knob

M20 Thread, 20mm Long | 10mm Spring-Loaded Pin | Black Plastic or Aluminium Lock-Down Knob | Screws Straight Into the Machine

The pin that sets your bench angle, seat height or foot plate - and the one that gets stripped, snapped or walks off first. This M20 x 20mm screw-in pop pin is the standard replacement for the spring-loaded adjustment pins on benches, racks and pin-loaded machines: a 10mm spring-loaded pin that snaps into the adjustment hole, and a lock-down knob that screws tight so the pin can't creep out under load. Choose the black ribbed plastic knob (54mm) or the machined aluminium knob (approx. 50mm) - same thread, same pin, same fit.

To adjust: loosen the knob, pull, move the slider, release. The pin springs back into the next hole and a quarter-turn of the knob locks it there. Screws into any M20 threaded boss - no tools, no bracket, no drilling.

Key Features

• Screw-in M20 fitting, 20mm thread: threads straight into the existing boss on the machine - a two-minute swap.
• Lock-down knob: screws tight once the pin is seated, so the adjustment can't work loose during a set.
• Spring-loaded 10mm pin: pulls back cleanly and snaps home into the next hole.
• Two knob options: black ribbed plastic (54mm, marked with the loosen-then-pull instruction) or machined aluminium (approx. 50mm, knurled grip) - select above.
• Hex flange: 22mm across flats for a spanner if it's been sitting a while.
• Ships from Sydney: small-parcel delivery Australia-wide.

Technical Specifications

Will it fit?

Three things to check on your old pin: the thread (M20 measures about 20mm across the outside of the thread), the pin diameter (10mm - it has to match the holes in the adjustment slider) and the thread length (20mm - long enough to reach through the boss). Both knobs share the same thread, pin and hex flange, so either one fits wherever the other does. If the thread on yours is noticeably smaller - about 16mm across - you want the M16 x 1.5 pop pin instead. For M12 or anything unusual, contact us with the model code from the machine's frame label and a photo, and we'll source the right one.

Warranty

Full terms are on our Warranty Policy page.

FAQs

Plastic or aluminium knob - which should I pick?
They're the same pin underneath. The black plastic knob matches the original fitting on most benches and racks and carries the loosen-then-pull marking; the aluminium knob is the pick for a metal-finish machine, a busy commercial floor, or anywhere plastic knobs keep getting cracked.

How do I install it?
Unscrew the old pin (loosen the knob, then turn the whole pin anticlockwise - a 22mm spanner on the hex flange if it's tight). Screw the new one in clockwise until the flange seats against the boss, pull the knob to check the pin retracts and springs back, then set your adjustment and tighten the knob.

What does "loosen then pull" mean?
The knob doubles as a lock. Once the pin is in a hole, screwing the knob down clamps it so it can't rattle out under load. To move the adjustment, back the knob off a turn first, then pull.

Where are these used?
Adjustable benches (back and seat angle), squat and half racks (J-hook and safety height on some models), leg press and hack squat foot plates, and seat and pad adjustments on pin-loaded machines - anywhere a spring pin sets a position.

Do you stock other sizes?
This is the M20 x 20mm screw-in. For the smaller 16mm thread on spin bikes and seat sliders, see the Pop Pin M16 x 1.5 x 30mm. For M12, longer pins or a full machine's worth, contact us and we'll quote from the supplier's parts list.

Shop More: Spare Parts | M16 Pop Pin | Magnetic Weight Stack Pins | Cable Pulley 150mm | Commercial Gym Equipment | Benches