We have these counterbores custom made for us by one of the top tooling manufacturers here in the USA.
These are a solid pilot TiAln coated solid micro grain carbide counterbore.
The .195 X .109 are built to work with our 4-40 socket head and short socket head screws.
The .223 X .109 are built to work with our 4-40 button head screws.
These are tighter than a standard #4 counterbore and will leave a .005″ clearance around our screw heads for a clean precision fit and look…
TIP: DO NOT clamp down the part you are counterboring. These do not like to flex . Hold your part free and you will get awesome results. We have counterbored hundreds of holes and are still using the very first one we ever bought!!!
NOTICE: We are happy to offer suggestions as how to use the tooling that we sell. However, our suggestions are exactly that.. We do not manufacture these tools. We have no control over how you as the consumer use these tools. We are NOT responsible for damage you cause to these tools during your learning curve using them. Carbide tooling is very strong and works extremely well on titanium. It is also very fragile and prone to breaking if not used properly.