Madlock Tech Page

Madco Machine Inc is a precision machine shop based in Red Deer Alberta, which prides itself on quality & innovation for regional industries as well as design of products on an international level. Madco Machine Inc. strives to meet industry needs and recognized a lack of truly theft proof trailer security, which gave birth to Madlock. 

After returning from a competitive weekend racing stock cars in Vegas the Madco crew tucked their prized race car hauler back in its spot until the next race. The following week their trailer was missing & racing in the US was put on hold. That was enough to leave a hole in our hearts.

After that unfortunate mistake they never felt any locks on the market were  tough enough. Covid times had slowed day to day operations at Madco Machine so the boys drove their efforts to design a lock that would make trailer owners feel secure. After filing patent, Madco Machine has one of the best locks available.


Madlock is "North American Made" in our own Madco Machine Inc manufacturing facility.  This gives us the ability to maintain the highest quality standards, making Madlock your best choice!

With the lock unlocked and pin dropped, slide the frame onto your stamped steel trailer coupler

Raise the black pin into the couplers ball socket

Push the key and key cylinder into the lock and turn the key 90° to lock.

Not all couplers are the same

What is a stamped steel coupler?

Stamped steel coupler

Stamped steel couplers are formed from one piece of steel. These couplers will have a flange that flares out from the bottom of the coupler to make a lip around the base. Madlock utilizes that flange to keep your trailer safe and secure.

Cast coupler

Some couplers are made from different materials such as cast steel and have a different design. Most cast couplers do not have a flanged lip at the bottom. If you have a cast coupler Madlock will not currently fit your application.

Do you have multiple trailers?

Madlock trailer locks can also be ordered as keyed alike as a pair or multiples.