We make furniture products with a huge variety of different shapes, sizes, material sizes, etc. Everything gets drilled and tapped for a simple leveler in the bottom. After the base or leg is finished, the holes are drilled and tapped by hand with battery powered drill. We used to use 1/4-20, but due to a number of issues with that, we switched to 5/16-18. There is either a cap on an open tube end that is drilled and tapped, or there is tubing across the bottom that is drilled and tapped. It is all 11ga or thinner.
We never had issues hand tapping 1/4-20 holes straight, however the 5/16-18 holes seem to be causing the drill to twist slightly, causing the tap to run in crooked, which is very obvious when the leveler is installed. Unfortunately switching back to 1/4-20 is not an option. Hoping you guys have some suggestions? I have attached a few pictures of various products so you can get an idea on what they look like.
Drilling and tapping the holes in a mill or drill press prior to welding seems like the obvious solution, but I'm really hoping to find a simple solution that will help the guys drill and tap the holes straight by hand after fabrication. Drilling and tapping the holes first has it's own set of issues and complications for us, but it's not out of the question.
Currently we drill the holes with a 1/4" drill bit, drop a dab of cutting fluid in the hole, and use a 5/16-18 HSS tapered tap.
We never had issues hand tapping 1/4-20 holes straight, however the 5/16-18 holes seem to be causing the drill to twist slightly, causing the tap to run in crooked, which is very obvious when the leveler is installed. Unfortunately switching back to 1/4-20 is not an option. Hoping you guys have some suggestions? I have attached a few pictures of various products so you can get an idea on what they look like.
Drilling and tapping the holes in a mill or drill press prior to welding seems like the obvious solution, but I'm really hoping to find a simple solution that will help the guys drill and tap the holes straight by hand after fabrication. Drilling and tapping the holes first has it's own set of issues and complications for us, but it's not out of the question.
Currently we drill the holes with a 1/4" drill bit, drop a dab of cutting fluid in the hole, and use a 5/16-18 HSS tapered tap.