Thickness To Be Cut
Teeth Per Inch
.030”-.080” .098”-.150” .177”-.354” .472”-.708” .944”-2.000”
3 ⁄ 32
1⁄16” ” ”” ”” ” ”
- - -
3 ⁄ 32
3 ⁄ 32
8-14 6-8 5-6 3-4 3-31⁄
Hollow Ground Hollow Ground Spring Set or Hollow Ground Spring Set or Swaged Spring Set or Swaged
High-Speed Steel Circular Saw Blade Recommendations
Notes: Recommendations are for hand-fed operations (3"-4"/sec.). The number of teeth can be increased proportionately to the feed rate for automatic feed operations, short of overloading the motor.
Typical Circular Saw Cutting Problems and Possible Corrections
1. Slow Feed Rate 2. Decrease Blade Penetration
1. Increase Feed Rate 2. Increase Blade Penetration
3. Support Material Continuously (Narrow Saw Slot)
3. Ensure Fence Is Parallel to Blade
4. Provide Hold Down 5. Increase Tooth Rake Angle
4. Use Blade Stiffener 5. Decrease Tooth Rake Angle
6. Ensure Teeth Are of Uniform Height
6. Ensure Blade Has Been Properly Sharpened
high-speed steel blades designed to cut Plexiglas® acrylic sheet may be used instead. These blades are made of alloy steel and are tempered to permit filing. The teeth should have a positive rake angle of 0° to 10° and should be of uniform height and shape. When cutting 0.150 inches or thinner sheet, the blade should be hollow ground rather than set. Teeth of uneven height will cause chipping of the Plexiglas® acrylic sheet and will place undue cutting strains on a few teeth. This may cause the saw blade to crack. The saw blades should be machine filed or ground.
For cutting very small quantities of Plexiglas® acrylic sheet, standard hollow ground, fine-tooth blades used for cross cutting wood or ply-tooth blades may be used. Table 1B lists the recommended high-speed steel circular saw blade information for cutting various thicknesses of Plexiglas® acrylic sheet.
Circular Blade Saw Operation
To minimize both chipping and overheating tendencies, circular
⁄ saw blades should protrude approximately 1 2 inch more than the
thickness of the Plexiglas® acrylic sheet. The work must be held firmly against the fence, which must be parallel to the saw blade.
Several sheets of Plexiglas® acrylic sheet can be cut at one time by stacking one on top of another. Suitably designed holding fixtures must be used when stacks of sheets are to be cut to close tolerances.
When unmasked sheets of Plexiglas® acrylic sheet are cut, it is necessary to take care to avoid scratching the surface of the sheet. Working surfaces should be covered with some soft material such as medium-density felt. The surface should be kept free of dirt and chips.
cloth will remove sawdust that clings to the material because of static electricity. The damp cloth will also dissipate the static charge.
When cutting Plexiglas® acrylic sheet on a table saw, a cutting board should be used for cutting stacked/clamped material or making a cut not parallel to another edge (angle cut). Figure 2 shows a suitable cutting board. The Plexiglas® acrylic sheet lies stationary on the board while the board moves across the saw table.
When cutting stacked Plexiglas® acrylic sheet to final dimensions with a panel saw, hold-down clamps should be used when feasible. This procedure will also help reduce chipping. The manual feed rate should be 3 to 4 inches per second (15 to 20 feet per minute) and should be uniform. The saw should be allowed to cut freely while maintaining the rated speed of the motor. Coolants are not required for most sawing operations, although, if exceptionally smooth cuts in thick sheet are needed, a fine spray mist of detergent in water or 10 percent soluble oil, compatible with Plexiglas® acrylic sheet, in water can be directed against the saw blade.
Sawdust and chips remaining on the surface of the Plexiglas® acrylic sheet after cutting may be removed by blowing with compressed air. Wiping the surface of the sheet with a damp
7. Use Blade With Greater Side Clearance