Forest Utilisation Chapter 2: Felling Tools, Axes, Saws and Saw Terminology

Forest Utilisation Notes · Chapter 2

Chapter 2: Felling Tools

Felling axes and their parts, saw terminology (pitch, set, kerf, gauge), cross-cut tooth patterns, bow, pruning and power saws, and the small logging tools used in Indian forests.

AxesSaw termsCross-cut sawsOther sawsHand toolsRevisionMCQ quiz

1. Axes

The axe is used for felling, trimming, splitting and grubbing. Its edge is carefully tempered and tested for toughness and strength.

Part or type	Detail
Felling axe head	Usually 1.5 to 2 kg, heavy axes up to 2.5 kg
Handle	Standard 90 cm (range 70 to 120 cm), of tough, straight-grained wood
Broad axe (squaring)	Edge 25 to 30 cm, head 2.5 to 3 kg; used to square logs into baulks
Bill hook	Short heavy blade for lopping branches and clearing undergrowth

Exam point: Felling with the axe alone wastes timber. 'Use of axe in felling' is among the causes of wastage, and felling with a saw saves 3 to 7% of butt timber.

2. Saw terminology

FaceThe edge of the tooth facing the direction of cutting.

BackThe opposite edge of the tooth.

SpaceThe distance from tooth point to tooth point.

GulletThe entire opening between two teeth.

PitchThe angle between the face of the tooth and the line through the tooth points.

SetThe amount by which the teeth are bent aside, so that the cut is wider than the blade.

KerfThe width of the saw cut.

GaugeThe thickness of the blade.

Memory trick: Set makes the kerf wider than the gauge, so the blade does not bind in the cut.

3. Cross-cut saws

Peg toothing

Teeth shaped like isosceles triangles; cut in both directions. The most common pattern for cross-cut saws.

Raker toothing

Cutter teeth sever the fibres and a raker (after every 2 or 4 cutters) clears the sawdust from the kerf. Faster in large logs.

Stem diameter	Saw length
Up to 30 cm	140 to 150 cm
30 to 70 cm	165 to 170 cm
80 to 100 cm and above	180 to 200 cm

A two-man cross-cut saw works with a stroke of 80 to 100 cm. The blade is about 85 mm wide (also 90 or 120 mm) and about 1.82 mm thick.

4. Other saws

Bow saw

Thin blade held tight in a tubular steel bow; blade 90 to 105 cm, cutting depth 25 to 30 cm. One-man saw for small poles and pulpwood.

Pruning saw

Teeth point backwards (reverse teeth) so it cuts on the pull stroke; used on long poles for pruning.

Power (chain) saw

Engine-driven chain on a guide bar; bars of 50 to 80 cm. Used for felling and cross-cutting, and needs a trained operator.

5. Small logging tools

Tool	Use
Wedges	Up to 30 cm long, 8 cm wide, about 5 kg; driven into the back cut to stop the saw binding and to direct the fall
Pickaroon	Hooked spike on a 85 to 100 cm handle for moving and lifting small logs and sleepers
Debarking spade	Removing bark from logs
Cant-hook	Lever with a hinged hook for turning and rolling logs
Log hook (timber tongs)	Lifting and carrying logs by two men
Measuring stick	Marking log lengths
Stem tightener	13 mm wire rope with a lever, to stop a stem splitting while it is cut
Cable tensioner (cable puller)	Two or three men can pull 3 to 5 tonnes; used to direct the fall of leaning trees

Exam point: Felling, logging and conversion are done by a two-man crew. Its kit is felling axes, a cross-cut or chain saw, wedges, files and a measuring stick.

6. Quick revision

• Axe head 1.5 to 2 kg; handle 90 cm. Broad axe for squaring.
• Pitch = angle of tooth face; set = bend of teeth; kerf = width of cut; gauge = thickness of blade.
• Peg toothing: isosceles triangles, most common. Raker toothing: cutters plus rakers that clear sawdust.
• Bow saw: one-man, 90 to 105 cm. Pruning saw: reverse teeth. Chain saw: 50 to 80 cm bar.
• Wedge stops binding; pickaroon moves small logs; cant-hook rolls logs; cable tensioner pulls 3 to 5 t.

7. Interactive MCQ Quiz

15 questions. Tap an option to see the answer and explanation, then go to the next question.

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