Lenox makes the best scissors I have ever owned. I've had a pair for about 4 years and they are still hotter than the Malco or Irwin brands. You can tighten the nuts if they start to loosen. but rarely needed. I have used them a lot. in ventilation and air conditioning technology. 26-30 sheet metal is not suitable. Drive Spike and even some S-Slip. I will not use other snippets. In my opinion the best on the market. The mouth is slightly larger than other brands. The only advice is to make sure the locking mechanism is facing away from you. Leaving the lock in this position will cause it to bend when cutting thick metal and then the lock will not close. but on the other hand the best on the market, then malco, but they don't last as long as these. And yes, I'm a pro. daily use. Don't waste your money on some crappy Stanley or Irwin or whatever. anything under $25 is a bargain for them. I carry left, right and bulldogs in my bag every day. If you only have one pair, use round, green-handled scissors - if you're right-handed.