A chainsaw cuts using a looped chain of sharp cutting teeth driven around a guide bar. The engine rotates a drive sprocket, pulling the chain at 40–75 mph around the bar — each tooth acts like a tiny chisel, shaving wood fibers with each pass.

Key Components

• ▸Engine/motor — 2-stroke for gas (50:1 oil mix); brushless motor for electric
• ▸Drive sprocket — engages chain, controls cutting speed
• ▸Guide bar — 12–20 inch flat metal rail for homeowner saws
• ▸Chain brake — stops the chain within 0.1 seconds on kickback
• ▸Oiler — automatically lubricates bar and chain during use

Aosheng 40V lithium-ion chainsaw — brushless motor design

Aosheng pole saw — tool-less chain tension system

A chain too loose can derail and cause injury. A chain too tight causes excess friction, overheats the bar, and snaps the chain.

The Snap Test

1. 1With the saw off and cool, pull the chain from the middle of the bar.
2. 2Correct: Chain pulls out ~⅛ inch (3 mm), then snaps back firmly.
3. !Sags more than ⅜ inch or drive links exit bar groove = too loose.
4. !Cannot pull chain away from bar at all = too tight.

Starting a Gas Chainsaw

1. 1Check chain tension, bar oil level, and fuel mix
2. 2Engage the chain brake (push the front guard forward)
3. 3Set choke to full, press primer bulb 5–6 times
4. 4Place on flat ground, brace the rear handle with your foot
5. 5Pull starter until engine "pops," move to half choke, pull again
6. 6Release chain brake before cutting — grip both handles

Aosheng chainsaw with kickback brake safety system

Most models reach 8–16 feet and can cut branches up to 5 inches in diameter without a ladder.

1. 1Extend pole to the length and lock all sections firmly
2. 2Position yourself to the side — never directly below
3. 3Undercut first: Saw upward ¼ diameter from below, 6–12" from trunk
4. 4Complete the top cut slightly further from the trunk
5. 5Use rope hook to control fall direction near structures
6. 6Final flush cut at branch collar — never into the trunk

Aosheng gasoline pole saw — AS-GZ260 model

Before You Start

• Inspect blades, apply lubricant spray before and after
• Corded models: Use an outdoor-rated extension cord, keep it behind you
• Check for hidden wires or fencing embedded in the hedge

Trimming Technique

• 1. Trim sides first — sweep bottom to top in wide arcing strokes
• 2. Taper base 10–15% wider than top for light to reach lower leaves
• 3. Trim top with blade parallel to ground; use string line as guide
• 4. Step back 10 feet frequently to check evenness

How often should I sharpen my chainsaw chain?

Sharpen after every 3–5 hours of cutting, or immediately if you notice the saw producing dust instead of chips, drifting to one side, or requiring extra pressure.

Can I use a chainsaw to trim hedges?

No. Chainsaws are not designed for the light, multi-directional cutting of hedge shaping. The chain can snag on small branches, causing violent kickback. Use a hedge trimmer for all hedge maintenance.

What is the best time of year to trim hedges?

For most shrubs: late winter or early spring (before new growth) and again in mid-summer. Avoid late fall — new growth stimulated by trimming can be killed by frost.

Why does my chainsaw keep stalling?

Most common causes: dirty air filter, clogged spark arrestor, or incorrect carburetor adjustment. Start by cleaning the air filter and spark arrestor screen. If stalling persists under load, the carburetor's high-speed needle may need adjustment.

How do I know if my hedge trimmer blades are dull?

Dull blades tear rather than cut, leaving ragged brown edges instead of clean green cuts. Blades can be resharpened with a flat file at a 10° bevel angle, or replaced — replacement blades typically cost $20–$50.

How long does bar oil last in a chainsaw?

A full bar oil reservoir lasts about as long as one tank of fuel. Always refill both together. Running with low-bar oil rapidly accelerates bar and chain wear — a new bar costs $15–$40.

Can a hedge trimmer cut small tree branches?

Most hedge trimmers handle branches up to ¾ inch (19 mm) in diameter. Beyond that, use loppers, a pruning saw, or a chainsaw — forcing thicker material bends the teeth and risks kickback.