Check if their transparency is set to 0 and then see where exactly the handle is when you select in during the test. Also I suggest to don’t use the “qPerfectionWeld”, it is kind of out dated.
Use: Tool Grip Editor - Roblox
Its more effective in positioning handles.
Also I will link you to my post about welding parts which can be useful if you are trying to keep the tool’s parts together in the correct position:Issues with animating a rigged weapon - #5 by Inc_X