Shackle Diameter for Roadmaster Quick Disconnect Padlocks

Updated 08/20/2019 | Published 08/19/2019

Products Featured in This Question

Roadmaster Base Plate Quick Disconnect Padlocks - Keyed Alike - Qty 4

(31)

$70.24

4" Carbon Fiber Digital Caliper

(26)

$12.46

Question:

Your drawing shows a shackle diameter of 1/4. I had used Masterlock No. 3 padlocks with 9/32inch dia. hardened steel shackles on my Roadmaster tow bars crossbar and the shackles on both locks sheared on a recent road trip allowing the crossbar to become disconnected on the passenger side of the vehicle. I measured the lynch pins that came with the tow bar and they measure 5/16. I contacted Roadmaster and they would not give me any any specifications on the padlocks that they use except the they use American Locks and Masterlock both brands are Masterlocks. Id like to use padlocks on my tow bar and crossbar connections however, if the Roadmaster locks have shackles smaller in diameter than what I used it scares the heck out of me. I had over $3000.00 in damage to my tow bar and towed vehicle it scraped a guard rail and I dont want to take any chances of the crossbar coming detached again. Can you have someone measure the diameter of the Roadmaster padlock shackles and it possible get the model numbers so that I can confirm the specifications?

asked by: Gregory C

Expert Reply:

I went out to the warehouse with the digital caliper # PTW80157 and found that the shackle of the Roadmaster Quick Disconnect Padlocks # RM-308 measures about 0.23" which is close enough to 1/4" that it is classified as a 1/4" shackle (technically it's about 15/64").

If you were using 9/32" shackles and they barely fit then that might be what the issue is. I would do some double checking with your setup and make sure that everything is seated properly and nothing is forced into place.

expert reply by: Jon G