Best ways to Manufacture Carbide Tools in ISO 4
Source steel rods are and carbide tips from Kennametal or from another reliable source.
Ensure thorough inspection of steel rods after chemical analysis
Cut steel rods to required length
Mill the front clearance angle of the recessing tools appropriately
Mill the side clearance angle on both sides of the recessing tools correctly and mill a positive top rake angle appropriately
Set and mill the tip pocket of the lathe tools shank parallel to the top rake face
Ensure the De burring of the tool shanks and stamp the designation as ISO 4 or as DIN 4976
Inspect all operations done so far.
Grind the carbide tip or carbide drill bit
Degrease the shanks of the cutting tools and the carbide tips
Procure Silver foil from an approved source
Apply suitable brazing flux on the tip seat area,
Create a sandwich of 2 silver foils and a copper foil in between with brazing flux in between them and place them on the tip seat area, apply brazing flux to the area of the tip that gets brazed, place the tip to be brazed on top of the sandwich of foils
Set the Induction brazing machine with a suitable induction coil and power tapping points.
Insert the recessing tool to be brazed with the carbide tip into the induction coil and start heating.
Stabilise heating when the steel shank turns from blue to mild red in colour.
Start heating again to take the carbide tip and the steel area surrounding it to the melting point of silver which is 650 deg C.
Press the tip into position with a pointer rod and allow the cutting tool to cool to
Remove the tool from inside the induction coil and place it in pre heated sand and allow it to cool to the room temperature.
Inspect the joint to ensure that the carbide tip is brazed properly onto the shank and that the silver has flown properly and that there are no gaps in the joint.
Set and grind the top rake angle, front clearance angle, side clearance angle and corner radius of on the carbide tips as per drawing and check.
Carry out final inspection of the tools for dimensions and defects on carbide tips prior to painting.