I remember my first padlock. It was a Master combination lock for my gym locker in seventh grade. The dial was blue, and if I’m mot mistaken, the combination was 13-24-4. Three turns clockwise, two counterclockwise, and clockwise to the final number.

Since those days I’ve grown a little more sophisticated about the locks I use. For a number of years I’ve had a Hampton padlock for my bicycle, with a case-hardened steel shackle, brass pin tumblers in a laminated steel body, coated with black rubberized plastic to make it weatherproof (and protect the bike’s paint). It’s a handsome lock, rectangular, squat, and strong, but it’s nothing compared to some of the locks on the market today. As far as I can tell, it’s now sold as the True Value hardware brand.

But much stronger and more versatile locks are now available, too. Medeco, makers of a famed patented cylinder lock whose keys cannot be duplicated except by authorized dealers, offers the same cylinder design for its padlock, making it virtually impossible to pick. The case hardened steel body incorporates steel inserts in critical areas of the cylinder to protect against drilling, cutting, and even sledgehammer attacks. According to the company’s specifications, the design protects against up to 10,000 lbs of bolt cutter force and up to 4,500 lbs of shackle pulling power.

Multi-Lock’s (www.mul-t-lockusa.com) KW line is a very impressive line of locks for just about any use imaginable. They range from a standard low-guard style familiar to every locker-room visitor, to a high-guard version of the same lock (the E-series), both with hardened Boron shackle and body, to a sliding bolt lock that allows almost no access to the shackle-bolt, to a chain lock with a 48-inch square link steel chain. Multi-Lock’s C- and T-series locks are heavy duty, while its E-series are considered Extra-Heavy Duty.

Medeco and KW locks are designed for real security, not just gym lockers (though using one would pretty much guarantee that your suit will still be there when you come back from your shower!) The technological improvements from decade to decade have made it possible to protect everything from storage boxes to car dealers’ lots with a lot more confidence than was possible even a generation ago.

For any padlock aficionado, one of the most delightful aspects of these versatile locks is the strides made in design over the past 20 years or so. While hardened steel is still the most commonly used material for the body, locks are available in solid brass or anodized aluminum that can be color-coded to meet Federal safety codes. Online you can find bright yellow cylinder padlocks that are shaped like a Vienna sausage, and of course the elegant black hardened boron of the KW E-series. Sizes, shapes, design, and materials used make it possible for a qualified locksmith to provide the padlocks that meet every customer’s exact need.

They’re all a far cry from the red, green, orange, and blue Master combination locks that used to line row after row of lockers in my middle school. And what a change for the better!