




🔐 Secure your world with the lock that means business.
The Master Lock ProSeries keyed padlock features a hardened boron alloy shackle and a heavy steel body with a shrouded design to protect against bolt cutters. Its dual ball locking mechanism and 5-pin spool pin cylinder provide superior resistance to pulling, prying, and picking. Finished in sleek black laminated coating, this industrial-grade lock is built for commercial and heavy-duty applications, delivering reliable, tough security you can trust.
| ASIN | B000E2NMWC |
| Best Sellers Rank | #399,071 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #1,015 in Keyed Padlocks |
| Brand | Master Lock |
| Color | Black |
| Control Method | App |
| Date First Available | January 6, 2006 |
| Finish Type | Laminated |
| Global Trade Identification Number | 00071649040078 |
| Included Components | Padlock |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1 pounds |
| Item dimensions L x W x H | 4 x 2.1 x 1 inches |
| Item model number | 6321 |
| Lock Type | Key Lock |
| Manufacturer | Master Lock, LLC |
| Material | Hardened Boron Alloy Shackle, Iron Shroud, Steel Body |
| Model Name | ProSeries |
| Number of Pieces | 1 |
| Product Dimensions | 4 x 2.1 x 1 inches |
| Recommended Uses For Product | commercial and industrial applications |
| Shape | Rectangular with rounded corners |
| Special Feature | Recycled |
| Style | Industrial |
| UPC | 071649040078 |
R**H
Very Heavy!
The lock is substantial and heavy! It paired nicely with the heavy duty chain I purchased. Black goes very well with the coated black chain against the black gate. Will deter the average thief.
D**E
A tough lock that is difficult (but not impossible) to cut.
I bought this lock to put on my storage unit after my Master combination lock froze (it was -30 degrees, Fahrenheit) and would no longer work. So far, it's been very reliable and it's an extremely well built and heavy duty lock. They can be cut, but the extra protection will make it a tough job. I know, because I had to cut the previous lock that was very similar, but was a combination lock instead of a keyed lock.
D**G
Good heavy duty lock
I'm not an expert, but have owned a number of types of padlocks. This lock is heavy, and the key mechanism works very smoothly. I would purchase again. 2 month update: after a few months in the sun, the main body of this lock turned a light gray. I purposely bought a black lock. So much for that.
M**Z
Outstanding product
Outstanding product would recommend this product to others
C**K
Doesnt work for Uhaul
Seems like a sturdy product but it doesnt fit uhaul trucks, which is how it was advertised and the reason I bought it. Had to go to Lowes last minute and choose another option.
G**N
Fits storage locker door tightly
Looks and feels very heavy duty. Doesn't leave any room in storage locker door for a thief to pry on it. Spare keys from a locksmith were $1.50 each. Locksmith told me that these locks are very tough.
C**R
High Performance Lock
I consider this lock to be military grade, which in this old warhorse's vocabulary means better than top quality. I trust it to secure a shipping container in a remote location.
M**P
Jammed shut and won't unlock after only 6 weeks.
What good is a padlock that won't unlock for its owner - it's worthless! It worked a few times, but now won't unlock when it's in place on my door's hasp - I'm locked out of my own shed.
Trustpilot
3 weeks ago
4 days ago