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Machine sawing tools \ Processing and machining technology - Sawing
Work regulations for metal circular saw blades
Use the correct tooth shape and tooth pitch for the different
materials and applications.
For pipe diameters and contact lengths smaller than 50 mm, use
tooth shape A (finely toothed).
Saw blades must be sawn-in due to the sharpness of the teeth. t
When doing so, the cutting speed must be reduced by up to 50%
until the teeth have lost their initial sharpness. Too fine Correct Too coarse
Use coolants to avoid overheating and ensure chips are removed.
Clamp the material at as short a distance as possible to avoid
vibrations.
The cutting speed and feed rate must be adjusted to match the
material and geometry (see cutting value table).
Guide to eliminating faults with metal saw blades
Wear on teeth Tool breakage
Larger tooth pitch if the saw blade clogs with chips Re-sharpen tool
Improve coolant feed or use correct coolant Reduce cutting speed
Teeth break off Clogging and material adhesion to saw blade
Improve poor chip removal Optimise feed
Use appropriate tooth pitch Optimise saw blade shape
Optimise workpiece clamping Coolant optimisation
Retraction of bandsaw blades
A new saw band has very sharp tooth tips due to the manufacturing method. In order to withstand the
cutting pressure when band sawing, the tooth tips should be circularly ground. Without this fine grinding
step, the high cutting pressure will lead to microscopic damage to the tooth tips and consequently to a
shorter service life of the entire saw band. Saw blades should be retracted to significantly increase the
service life. The following steps describe proper retraction:
The correct band speed must be used for the material to be cut.
Reduction of the feed speed or feed power of the saw to reach a cutting speed of 20% to 50% of the 1 2 3
normal cutting speed. Mild steels require a greater reduction in velocity than materials that are more
difficult to machine. ① New saw band ② With retraction ③ Without
The first cut should be initiated at reduced speed with care taken to ensure the teeth form a shaving. As retraction
soon as the blade is fully submerged in the workpiece, the feed can be increased slightly.
The feed speed should be successively increased across several cuts until the normal cutting speed is
reached (total cutting area 60 to 118 inch /150 to 300 cm ) 2
2
It is important to note that slight adjustments must be made to the band speed during insertion in the
case of excessive noise or vibration. As soon as the saw blade has been retracted, the recommended
band speed should be used.
Rules for working with metal circular saws
Where contact length is less than 50 mm or in the case of thin-walled pipes and profiles, only tooth pitches with 0° chip angle may be used.
The lifespan of a saw blade depends on controlled sawing-in: Reduce cutting pressure (feed) by 50% for the first cuts, then increase feed to the optimal value
after approx. 300 cm surface has been cut.
As a general rule, the cutting speed is determined by the strength, type and cross-section of the sawn material. The higher the strength, the lower the speed that
must be selected. A higher speed can be used with smaller cross sections than with larger cross sections. The chip shape indicates whether the speed and feed
rate are selected correctly. The chips should be loosely coiled. If the chips are thin, the feed should be increased; thick chips are a sign of the speed being too
high.
The material should be clamped in order to help the saw blade work with as little vibration as possible.
Use of coolant prevents overheating and aids faster chip removal.
Use of the highest permitted band width for the machine ensures sufficient stability at higher feed forces. When cutting curves, the blade width depends on the
smallest radius which is to be cut (see cutting value table).
Radius (mm) 3 8 15 30 38 65 100 140
Band width (mm) 3 5 6 8 10 13 16 20
Source: Hahn+Kolb Werkzeuge GmbH
Technical data subject to change. www.iconridge.com
Availability subject to country specific rules and regulations. 283
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