Tree work words: saws and cutting

Saw and felling words change from country to country. The same notch is an undercut in the United States, a directional or sink cut in the UK and a scarf in New South Wales. This page lists what each named source says a word means, so a reader can match a term heard on a crew to a written definition.

Every meaning is written in our own words from the page named in its row. A word that none of those pages defines is not listed. The wider A to Z list is the tree work glossary.

Words and meanings

Term	Meaning	Source
Back cut (backcut)	The final cut in a felling job, in OSHA's wording. The New South Wales code calls it the final release cut and puts it on the opposite side of the trunk from the scarf.	OSHA logging standard 1910.266, definitions and felling rules; SafeWork NSW tree work code, glossary
Undercut	In OSHA's definition, a notch cut into the tree to steer the direction of the fall and to help prevent splitting or kickback.	OSHA logging standard 1910.266, definitions and felling rules
Scarf	The New South Wales word for two cuts that form a notch. The notch sets the direction of fall when felling or topping, or the direction of break when a branch is taken off.	SafeWork NSW tree work code, glossary
Directional or sink cut, hinge, main felling or back cut	The UK HSE names these three as the parts whose combination keeps control of a fell, and says the cuts have to suit the tree's size and form.	UK HSE page on working with chainsaws
Hinge	OSHA's felling rule says the back cut must leave enough hinge wood to hold the tree to the stump during most of its fall, so the hinge can guide the fall in the intended direction.	OSHA logging standard 1910.266, definitions and felling rules
Face cut	The horizontal cut that the back cut sits above, in OSHA's felling rule. OSHA's note says open face felling uses two angled face cuts instead.	OSHA logging standard 1910.266, definitions and felling rules
Open-faced notch and bore cut	The UGA circular describes an open-faced notch followed by a bore cut through the tree to form the hinge. It says this makes a barber chair less likely, because the tree fibres are less likely to be stretched to breaking.	University of Georgia Extension circular C 1243
Barber chair	The circular describes the trunk splitting when the pull forward is strong enough to split it but too weak to fold the hinge. The base of the trunk rises and the top comes down.	University of Georgia Extension circular C 1243
Stump jump	The circular describes the hinge giving way so the tree leaves the stump and falls free.	University of Georgia Extension circular C 1243
Setback	The circular describes the tree sitting back onto the blade during the bore cut or back cut and pinching the saw. It ties this to a tree with back lean.	University of Georgia Extension circular C 1243
Entanglement	The circular describes a tree being felled that is caught in vines or hits branches or another trunk and hangs up.	University of Georgia Extension circular C 1243
Lodged tree (hung tree)	In OSHA's definition, a tree leaning on another tree or object so that it cannot reach the ground. The UK HSE and the New South Wales code say hung up.	OSHA logging standard 1910.266, definitions and felling rules; SafeWork NSW tree work code, glossary
Domino felling	Partly cutting several trees that are left standing, then pushing them over with a pusher tree, in OSHA's definition.	OSHA logging standard 1910.266, definitions and felling rules
Driving trees	Felling one tree into one or more others to bring them down, in WorkSafe New Zealand's forestry glossary.	WorkSafe NZ forestry glossary, appendix 1
Danger tree	In OSHA's definition, a standing tree that is a hazard to workers, for reasons such as damage to the roots, trunk or limbs, or its lean.	OSHA logging standard 1910.266, definitions and felling rules
Snag	Any standing dead tree or part of one, in OSHA's definition.	OSHA logging standard 1910.266, definitions and felling rules
Spring pole	In OSHA's definition, a tree, limb or sapling held under strain by the weight or pressure of something else. The circular describes the hazard as a violent release of energy when a saw cuts wood under great tension.	OSHA logging standard 1910.266, definitions and felling rules; University of Georgia Extension circular C 1243
Kickback	The UK HSE defines it as the sudden uncontrolled upward and backward movement of the chain and guide bar towards the operator, which can happen when the chain at the nose of the bar hits an object.	UK HSE leaflet Chainsaws at work
Kickback zone	The upper quadrant of the guide bar nose, in the New South Wales glossary. The circular calls it the top quarter of the bar.	SafeWork NSW tree work code, glossary; University of Georgia Extension circular C 1243
Pinch kickback	The circular describes the bar being pinched by the wood being cut. A pinch on top pushes the saw back into the operator. A pinch underneath pulls the saw forward.	University of Georgia Extension circular C 1243
Chain brake	A part that stops the chain. The circular lists it among five essential safety features and says it is also engaged by the inertial forces of a kickback. The HSE leaflet lists the chain brake among the parts to be checked for damage or wear.	University of Georgia Extension circular C 1243; UK HSE leaflet Chainsaws at work
Chain catcher, right hand guard	The circular says these two work together to protect the operator if the chain breaks or comes off.	University of Georgia Extension circular C 1243
Throttle lock	The circular describes it as a part that blocks accidental throttle advance, so the operator keeps a firm grip as the saw speeds up.	University of Georgia Extension circular C 1243
Low-kickback chain (safety chain)	The HSE leaflet says a properly maintained chain brake and a low-kickback chain reduce the effect of kickback but cannot prevent it entirely.	UK HSE leaflet Chainsaws at work
Rear-handled and top-handled chainsaw	The HSE leaflet describes two designs. Rear-handled saws have the rear handle at the back and are gripped with both hands. Top-handled saws have the rear handle over the top of the engine, and the leaflet says they are for trained, competent arborists working off the ground.	UK HSE leaflet Chainsaws at work
Pole saw	A chainsaw bar on a telescopic pole, hydraulically or engine powered, in the New South Wales glossary. The same glossary says a hand-operated version carries a toothed blade.	SafeWork NSW tree work code, glossary
Safety mitt	A leather mitt attached to the front handle of a chainsaw but free to rotate on it. WorkSafe New Zealand says it protects the hand and keeps it on the handle in a kickback.	WorkSafe NZ arboriculture code, definitions
Drop start	Starting a chainsaw by pushing it away from the body with one hand while pulling the starter cord with the other. WorkSafe New Zealand's code says this is not an approved work practice.	WorkSafe NZ arboriculture code, definitions
Extended arm technique	The New Zealand code's name for a method of starting a chainsaw while aloft.	WorkSafe NZ arboriculture code, definitions
Chaps	A form of leg protection worn when operating a chainsaw, in the New South Wales glossary. More in chainsaw clothing labels.	SafeWork NSW tree work code, glossary
Buck, bucking, cross cutting	Cutting a felled tree into logs, in OSHA's definition. The New South Wales code defines bucking and cross cutting as the same job, sawing a felled tree or limbs into smaller sections.	OSHA logging standard 1910.266, definitions and felling rules; SafeWork NSW tree work code, glossary
Limbing	Cutting branches off felled trees, in OSHA's definition. The New South Wales glossary words it as removal of limbs from a fallen tree.	OSHA logging standard 1910.266, definitions and felling rules; SafeWork NSW tree work code, glossary
Fell, feller (faller)	To cut down trees, and the worker who does it, in OSHA's definition. WorkSafe New Zealand's forestry glossary says to cut, chop, push or pull down a standing tree or part of one.	OSHA logging standard 1910.266, definitions and felling rules; WorkSafe NZ forestry glossary, appendix 1
Tree felling	In WorkSafe New Zealand's arboriculture code, making and placing felling cuts to bring a standing tree safely to the ground. The code says height reductions and structural or formative maintenance are outside that meaning.	WorkSafe NZ arboriculture code, definitions
Topping	In the New South Wales glossary, removing the upper canopy of a tree in one operation by felling while aloft. Other sources use the word for a pruning practice, so the word alone does not say which is meant.	SafeWork NSW tree work code, glossary
Breaker bar, cant hook, wedge	The HSE page names breaker bars and wedges as felling aids. The leaflet's figures show a breaker bar with a cant hook, and its text names pulp hooks, log tongs and high lift wedges as aid tools.	UK HSE page on working with chainsaws; UK HSE leaflet Chainsaws at work
Felling cushion	The HSE leaflet describes a cushion inflated with the saw's exhaust gas, used instead of wedges to force a tree over.	UK HSE leaflet Chainsaws at work
Grinder (stump grinder)	Portable machinery used to reduce or remove stumps by grinding, in WorkSafe New Zealand's arboriculture code. More in chippers and stump grinders.	WorkSafe NZ arboriculture code, definitions

Reading these sources

The US definitions come from the logging standard, 29 CFR 1910.266, which OSHA applies to logging operations. Tree crews borrow its words, but the standard itself names logging as its scope. The UK words come from the HSE leaflet Chainsaws at work and the HSE page on working with chainsaws. The Australian words come from the New South Wales tree work code of practice, and the New Zealand words from WorkSafe New Zealand's arboriculture code and its forestry glossary.

The University of Georgia circular is an extension publication about common felling accidents. Where it names a hazard, the row says what the circular says the hazard is. It does not teach the cuts.

For what the rules say about chainsaw protective clothing, see chainsaw protection by country. For the climber's side of the vocabulary, see tree work words: climbing.

Contains public sector information published by the Health and Safety Executive and the Forestry Commission and licensed under the Open Government Licence v3.0. Contains material from the SafeWork NSW Tree work code of practice, which SafeWork NSW publishes under a Creative Commons Attribution 4.0 licence. Contains material from WorkSafe New Zealand publications. The wording above is ours.

Tree work words: saws and cutting

Words and meanings

Reading these sources

Sources