Muscles of Iron

Secure Your BarWith Shaft Collars

Logo for MOI Sticks Collection article.


Some strength companies are reselling shaft collars under the name Allen collars and marking them up three or four times the cost. The shaft collar (Figure A) is a steel ring collar with shallow splits in the radius. A collar of proper size can be tightly secured against any shaft simply by tightening the collar screw with an Allen wrench.

Shaft collars are available in a variety of bore (center hole) sizes: 3/4-inch, 1-inch, 112-inch, diameters, etc. The primary application of a shaft collar is to center and hold a pulley sheave onto a center rod in an industrial setting (Figure B). However, they are also serve perfectly for barbell and dumbbell collars (Figure C) and for many other applications involving strength-training equipment.

Illustration showing shaft collars being used on a winch-hoist application and secured on a length of schedule 40, 3/4-inch pipe.
Figures A - C
Drawing by and courtesy of Chris ‘Sticks’ Bostick.

I purchased a lot of 10 shaft collars for $1.75 each from Fastenal. They are also available from Global Industrial, M.S.C. Supply, McMaster-Carr, etc. Shop around and I'm sure you'll beat the price of $29.95 for four pieces one reseller I know SHAFTS people for! Don't get shafted! LOL.

Notes from from the editor:

Since this article was written by Sticks (2014), the cost of steel and shaft collars have increased. You can still find good prices, though. For example, I found (January, 2021) that Amazon sells a package of four carbon steel, black oxide coated, single-split, 1" bore shaft collars for $13.99 + shipping (shipping is free for orders over $25).

Keep in mind that a shaft collar must have a slightly smaller bore size than the actual diameter of the shaft it is to be tightened on. For example, a 1-inch (bore size) shaft collar will work perfectly with a schedule 40 3/4-inch nominal pipe (actual outer diameter is 1.050 inches). However, if your barbell has an OD 1 inch or slightly less (as mine is), it will require a set of 3/4" (bore) collars.

Bonus: Budget Weight Holders

Need extra weight holders for your 2"x2" square tubing power rack? I saw a popular brand for sale on the net for $50.00 per pair! Figure D illustrates a much more economical set-up. It consists of two 5-inch long, one-inch diameter hex-steel bolts ($5.50 each), two bolt nuts ($0.50 each), and two one-inch (bore) shaft collars ($1.75 each). Total investment for a pair of great weight holders: $12.75 and no shipping. Sweet.

Illustration of taping and securing a bolt to a power rack to hold a barbell.
Figure D
Bolt weight holder. Drawing by and courtesy of Chris ‘Sticks’ Bostick.

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