Choosing a log splitter: tonnes, log sizes and safety features

A hydraulic log splitter pushes a log against a wedge (or the wedge into the log) with a ram. The headline figure — 5 tonnes, 7 tonnes, 8 tonnes — is the splitting force. It is a useful guide, but it isn’t the whole story, and it doesn’t tell you on its own whether a machine will take your logs.

This guide compares three SIP machines because SIP publishes the same set of figures for each, which makes a fair comparison possible.

Start with the maker’s log size, not the tonnage

Every splitter has a maximum log diameter and a range of log lengths, set by the maker for that machine. They are the first thing to check against the wood you actually have.

• SIP 5 ton horizontal electric: logs 50–250 mm across and 200–520 mm long.
• SIP 7 ton vertical electric: logs 80–300 mm across and 100–550 mm long.
• SIP 8 ton petrol: logs 70–300 mm across and 120–520 mm long.

If your stove takes 25 cm logs and your rounds are mostly under 25 cm across, the 5 tonne machine’s range covers them. Bigger rounds point to the 7 or 8 tonne machines. SIP rates all three for splitting softwoods and hardwoods.

Horizontal or vertical

• Horizontal splitters lay the log on a bed at working height. SIP’s 5 tonne model sits inside a safety cage and the wedge returns to its start position on its own after each split.
• Vertical splitters stand the log on end, which SIP says gives a smaller working footprint. The 7 tonne model has operator handle guards to help keep hands away from the splitting area, and a ram lock.

Electric or petrol

The two electric SIP machines plug into a 230 V 13 A supply (2.2 kW and 3 kW motors), so they suit a garage, yard or garden near the house. The petrol model has a 196 cc engine and a 3.6 litre tank and sits on rough-terrain wheels, so it can go to the wood pile instead.

A petrol splitter brings two extra jobs: it must only be run outdoors because of carbon monoxide (the NHS lists engines run in enclosed spaces such as garages as a cause of CO build-up), and you need to store fuel safely. See generators and carbon monoxide — the same rules apply to any engine — and storing petrol at home.

Weight and moving it

• 5 ton horizontal electric: 50 kg, with wheels and a handle.
• 7 ton vertical electric: 109.2 kg, with wheels and a handle.
• 8 ton petrol: 93.5 kg, with large rough-terrain wheels and a pull handle.

If the splitter will be wheeled out of a shed each time, the difference between 50 kg and over 100 kg matters.

Safety features to look for

From SIP’s own feature lists:

• Guarding — a cage (5 tonne), operator handle guards (7 tonne) or steel guarding around the splitting area (8 tonne).
• Controls — the electric models have an NVR (no-volt release) switch; the 7 tonne model adds a ram lock. Read the manual for exactly how the controls are meant to be used, and never defeat them.
• Auto-return — the 5 tonne model’s wedge returns automatically.

Follow the manual on where to stand and how to load each log, and keep other people well back while you split.

Noise

SIP gives noise levels for each machine: 89.9 dB(A) at full load for the 5 tonne, 89.7 dB(A) for the 7 tonne and 108 dB(A) for the petrol 8 tonne. For comparison, the Noise at Work Regulations require employers to provide hearing protection where daily exposure reaches 85 dB(A). Plan on wearing ear defenders — see noise and hearing protection.

Hydraulic oil

The splitters use hydraulic oil — 3.5 litres of HV22 in the 5 tonne model, 4 litres of HV22 in the 7 tonne and 3.5 litres of HP32 in the petrol 8 tonne, according to SIP. Check the level and change it as the manual says.

Quick checklist

1. Measure your biggest rounds (diameter and length) and compare them with the maker’s stated range.
2. Decide where it will be used: near a 13 A socket, or out in the field.
3. Check the weight against how far you’ll move it.
4. Look for guards, a ram lock or auto-return, and controls you understand.
5. Budget for ear defenders, gloves and eye protection.

Search Amazon for electric log splitters.