Power Saws

Question 1

What are the four commonly used saws used by millwrights?

Answer 1

Power hacksaw-not common

Horizontal bandsaw (cut-off saw)

Vertical bandsaw (contour)

Abrasive cut-off saw

Question 2

What is SPM?

What machines measures speed that way?

Answer 2

Strokes per minute

Power hacksaw.

Question 3

Number of saw blade teeth per inch?

Answer 3

Blade pitch

Question 4

Thickness of the body of a blade behind the teeth?

Answer 4

Blade gauge

Question 5

Distance from the tip of the tooth to the back of the blade?

Answer 5

Blade width

Question 6

The width of the cut the blade makes?

Answer 6

Blade kerf

Question 7

The way the individual teeth are bent out of line with the blade body?

Answer 7

Blade set

Question 8

What is a horizontal bandsaw used for?

How is the size measured?

Answer 8

Most commonly used as a cutoff saw.

Measure by the largest size of material it can cut.

Question 9

What is SFPM/SMPM?

Answer 9

Surface feet per minute/surface meter per minute

Question 10

Why should coolant and cutting fluids be used?

Answer 10

-Provides lubrication and cooling
-Prolong life of saw blade
- water is best but causes rust, oil does not cause rust but not as efficient.
- soluble oils and chemicals need to be added to the water to prevent rust

Question 11

What properties should chemical agents for cutting have?

Answer 11

Provide rust control

Have resistance to rancidity

Reduce heat generated from cutting

Separate waste chips from workpiece

Question 12

What is a vertical bandsaw (contour) used for?

Answer 12

Cutting shapes 
Notching 
Slotting
Internal contour sawing
Angular cutting
Splitting 
Three dimensional shaping

Question 13

How is capacity measured with a vertical band saw?

Answer 13

Throat distance

Question 14

What are the 3 common blade materials and there properties?

Answer 14

High carbon steel-either hard backed blade for straight accurate cuts in low carbon steel and non-ferrous metals. flexible backed blades for ferrous metals and contoured surfaces

Bimetal-greater wear and heat resistance.

Tungsten carbide-same as bimetal blades but have a carbide tip. Faster, smoother cutting

Question 15

What are the three types of teeth for band saw blades?

Answer 15

Standard-general purpose

Hook tooth-soft metals, plastics, wood

Skip tooth-soft materials or workpieces with thick cross sections

Question 16

What are the three blade sets?

Answer 16

Raker-general purpose

Wavy- distinct change in cross section ie, pipe

Straight/alternate-rough fast cutting

Question 17

What are the two types of pitch on a bandsaw blade?

Answer 17

Variable-varies in tooth size,depth and gullet.

Constant-uniform spacing of teeth, gullet depth and rake angle. (General purpose)

Question 18

Soft materials require what pitch of blade?

Harder materials require what pitch of blade?

Answer 18

Soft materials require courser pitch(fewer teeth)

Harder materials require finer blade.

Question 19

Annealing is?

Answer 19

Takes the hardness and brittleness out of the blade after welding

Question 20

What is friction sawing?

Answer 20

Friction sawing cuts steel by generating enough heat to soften the steel ahead of the blade.

Can not use the method aluminum or copper because they dissipate heat to quickly.

Question 21

What is a cutoff saw used for?

Answer 21

To cut hardened metals, glass, ceramic, brick and stone.

Best suited for cross sections under 2 inches

Question 22

What are the 3 types of abrasive grit for cutoff saws?

Answer 22

Aluminum oxide-cutting steel and most other materials

Silicone carbide-non ferrous metals

Diamond-ceramic, stone and brick

Question 23

Tensioning a horizontal bandsaw blade is done by?

Answer 23

Tensioning the bandsaw blade just tight enough to hold it on the pulley’s.

Start and stop the machine quickly slowing the blade to make a couple turns around the pulleys. This will position the blade on the pulley.

Tension blade

Question 24

If bandsaw blade jumps and shutters it means?

Answer 24

The feed is to high

Question 25

When should I wear gloves while operating a bandsaw?

Answer 25

Only when changing the blade and handling roughy dirty material.

Not while machine is in operation.

Question 26

How do you track the blade on a vertical band saw?

Answer 26

The head houses the upper pulley, which can be tilted from side to side by a hand wheel mounted in the centre of the pulley.

By adjusting the pulley tilt you can track the blade to ride in the centre

Question 27

Why does starting a new blade in a old unfinished cut tend to jam on a bandsaw?

Answer 27

Because the old blade probably cut a slightly smaller kerf (width of cut)

Question 28

What is the grinding wheel for and a vertical bandsaw?

Answer 28

To square the ends of the blade and to grind off the weld after welding blade together

Question 29

If blade ends are not square what will happen after welding?

Answer 29

Blade will have a slight bow in the area of the weld

Question 30

Where should the weld be on a vertical band saw blade?

Answer 30

At the bottom of the gullet

Question 31

When grinding the welded blade make sure to not grind teeth and check the thickness after with the______?

Answer 31

Blade gauge

Grinding and rapid cooling may cause the blade to become brittle and need to be annealed again. Check blade by bending back and forth near the weld area