The standard procedure for regrinding carbide and stellite tipped blades is as follows:
1. Cleaning the blade
Start by cleaning the blade thouroughly. Use a cleaning agent that will remove resin.
Do not scrape the blade with a sharp object as this can cause burrs and accelerate
coating of the blade. Instead wipe the blade clean and dry with a soft rag.
2. Replace damaged carbide tips
Check if any of the teeth are damaged or missing. Replace them with teeth of the same type.
If several damaged teeth are close together they should not be brazed in sequence. Instead
you should braze alternate teeth (1, 3, 5) and then go back (2, 4, 6, etc.)
The procedure for brazing carbide tips is briefly as follows:
A Remove any particles of carbide by heating and grind all traces of braze from the seat.
B If necessary to degrease, wash with acetone or the like.
C Brush the tooth seat with flux.
D Place the braze on the tooth seat using pliers and brush with flux.
E Line up the tooth with the seat using pliers.
F Hold the tooth on the seat during brazing.
G Wash off any traces of flux in warm water.
If using high frequency brazing we
recommend a temperature of 730°C.
If gas brazing, heat gently with a flame
until the braze melts. We recommend
a silver braze of the 3 layer type with
a paste type flux. It is recommended
that you use a fume extractor during
3. Levelling and tensioning
Check that the blade is flat and correctly tensioned. Levelling is easier if you have a well organised work area and accurate measuring tools. Make sure the light is coming from directly ahead. If the blade is correctly tensioned you should see a gap across the full diameter.
A higher tension is required at higher cutting speeds. The blade should be uniformly tensioned across its full diameter. Check with a steel rule roughly equal
in length to the radius of the blade. Remove any
high or low spots using a roundhead hammer.
Otherwise they will cause the blade to run unevenly.Place the blade on an anvil and check that it is flat on both sides using a long rule. If the blade has high spots or is uneven it should be levelled using a cross-faced hammer.
4. Grinding edge of tooth
Blades with guard teeth (S)
must be ground as follows:
x = 0,5-0,6 if kerf <= 2,5 mm
x = 0,7-1,0 if kerf > 2,5 mm
5. Grinding carbide tips
These are the most important factors for achieving good
• A stable grinding machine with good bearings.
• The blade must be properly secured in the mach
ine and gripped as close to the point of grinding
• Right choice of grinding wheel.
• Right grinding data.
• Good supply of coolant.
A. Side grinding of replaced carbide tips.
Grind to the same radial and tangential clearance angles as the original carbide tips.Check that the replaced teeth have the same kerf and clearance as original teeth.Recommended grit size of diamond wheel for side grinding is D91 or D126. When grinding, ensure blade is mounted centrally!
B. Front grinding
Grind no more than necessary, usually 0,05-0,1 mm. Do not change the original rakeangle and grind the whole tip. Recommended grit size of diamond wheel for frontgrinding is D76 or D64 for normal standards of finish, and D54 or D46 where a better surface finish is required. When grinding, ensure blade is mounted centrally!
C. Top grinding
Grind the blade to maintain the original tooth shape and clearance angle. Check that both teeth are of the same height (tooth shape BA). The maximum allowable difference is 0,05 mm. In the case of tooth shapes EA, EAX and EAXH there must be a difference of 0,3 mm between straight and trapezoidal teeth. In the case of EAM shape teeth the difference should be 0,2 mm. Recommended grit size of diamond wheel for top grinding is D54 for single wheel, or D126/D46 for a twin rim wheel. If the blade is used to cut perspex we recommend D20B. When grinding, ensure blade is mounted centrally!
6. Grinding wiper slots
The wiper slot must be sharp and should be re-sharpened every second time the carbid tips are resharpened. Grind the wiper slots with the blade supported on rest with the blade supported so
that the blade and wiper slot are a right angles to the grinding wheel. Grind as close to the periphery of the grinding wheel as possible.
7. Grinding hollow ground carbide tips
Use a grinding tool with a diameter suitable for the kerf of the blade.
Kerf: 3,0 mm
Tool diameter: 7,0 mm
Kerf: 3,6 mm
When grinding, ensure the blade is mounted centered!