Free Weldon flats, ground where your holder needs them.
Shop-ground flats are one of the most common causes of inconsistent results and early tool failure. So RobbJack grinds the set-screw flat at the factory, at no charge, located from your own toolholder and stickout.
Why we don't want you grinding flats
Flat in the wrong place
The set screw lands on the 45° or the edge of the flat instead of seating on it, so the tool can creep, pull out or break.
Off-center or tapered grind
A hand-ground flat pushes the tool off center. One tooth does more of the work, so runout goes up and tool life goes down.
Heat and burrs on carbide
Grinding a flat in the shop can heat-check the carbide shank and leave burrs, and those start the cracks that end a tool early.
Two measurements. We do the rest.
Measure A once per holder
From the holder face (the tip of the toolholder) to the corner of the set screw's flat tip, where the flat meets the 45°. Not where the 45° starts. It's the same for every tool that goes in that holder.
Tell us B for the job
Your desired stickout: holder face to the cutting tip. Your programmer usually already has this number.
We grind the flat at A + B
The flat's corner is ground A + B from the cutting tip. Every tool of that part number arrives identical and ready for the holder.
Flat-location template
One row per tool and holder. Fill it in and send it with your order or quote request, to your RobbJack representative or distributor, or to sales@robbjack.com. The Excel version adds A + B for you.
- Order with the -FL suffix, or note “flat” on your quote request.
- No measurements? We grind a standard Weldon flat, still at no charge.
- Only angular flats (whistle notches) carry a charge.
Even better: holders that hold
A side-lock holder pushes the tool off center. Where rigidity matters most (long reach, tough alloys, heavier radial engagement) consider:
- Shrink-fit: strongest grip and lowest runout, on a plain shank (no flat needed).
- Hydraulic: low runout and good damping, with fast tool changes.
- Damped (anti-vibration): for long reach, to stop chatter so the tool holds its parameters.
Not sure which fits your job? Ask an applications specialist.
Order your tools with the flat already on them
Send A and B with your order, and every tool arrives ready for the holder.