Buying a Used Slow Speed Shredder: Single Shaft, Twin Shaft and What to Check

A slow speed shredder is a low speed, high torque machine that tears waste between toothed shafts rather than smashing it at speed. If you are buying a used one, decide first whether you need a single shaft, twin shaft or four shaft machine for your material, then check the cutters, shafts, bearings, gearbox or hydraulic drive, chamber and service history before you pay. A test run with your own material tells you more than any photo.

What a slow speed shredder does

Slow speed shredders turn rotating shafts fitted with cutting teeth at low revs, using torque to grip, tear and size material. Because they run slowly, they tend to cope better with contaminants such as stones or the odd bit of metal than high speed machines, and they produce less dust and noise. They handle green waste, waste wood, mixed and bulky waste, tyres, plastics and some metals.

Many operators use them as a primary or pre-shredder, breaking material down before it goes to a screener, a finer shredder or a hammer mill. If you are setting up a full processing line, read our wider guide to buying used waste and recycling machinery as well.

Single shaft, twin shaft or four shaft?

The number of shafts decides what comes out of the machine, so match it to your material and end product.

• Single shaft: one rotor with cutters, usually with a hydraulic ram pushing material against it and a screen under the rotor that controls the output size. Good where you need a more consistent particle size, for example waste wood, plastics or fuel production. Examples on PTT include the Doppstadt DW 3060 single shaft slow speed shredder and the 2019 Untha XR3000C tracked single shaft shredder.
• Twin shaft: two counter-rotating shafts that pull material in and tear it. Output is coarser and less uniform, but these machines take bulky, mixed and dirty material well, which is why they are popular for pre-shredding. See the Hammel VB 950 DK twin shaft shredder and the 2021 McCloskey VTS95 twin shaft shredder.
• Four shaft: four shafts, often with a screen, giving a finer and more even output in one pass. They suit jobs such as confidential waste or electronics where size control matters, for example the 2022 Untha RS40 4 shaft slow speed shredder.

Also decide between a mobile machine (tracked or on a hook-lift or trailer chassis) that can move between sites, and a static electric unit fed by a conveyor or loader. Electric machines need the right power supply on site, so check that before you buy.

What to check on a used slow speed shredder

Get the make, model, year, hours and service records first, then work through these checks, ideally in person.

Cutters, teeth and shafts

Look closely at the cutting teeth and discs. Rounded, chipped or missing teeth cut throughput. Find out whether the teeth are bolt-on or welded, because bolt-on teeth are easier to replace. Check the shafts for cracks, bends or signs of heavy weld repair, and look at the counter comb or scrapers, which keep material from wrapping around the shafts.

Bearings, seals and drive

Shaft bearings and seals take a lot of load. Listen for knocking or grinding when the shafts turn, and look for oil or grease leaking around the shaft ends. Machines are driven either through a gearbox or hydraulically, so check gearbox oil condition and noise, or the hydraulic pumps, motors and hoses for leaks and damage.

Chamber, hopper and screen

Inspect the cutting chamber walls, hopper and wear liners for cracks, holes and patch welds. On single shaft and four shaft machines, check the screen and the ram, including the ram guides and hydraulic cylinder. A worn screen changes your output size.

Engine, electrics and controls

On diesel machines, check the engine starts easily from cold, runs without heavy smoke and has a service record. On any machine, test the control panel, emergency stops and the auto-reverse function, which reverses the shafts when they jam or overload.

Conveyors, magnets and chassis

Check the discharge conveyor belt, rollers and drive, and the overband magnet if fitted. On tracked machines, check the tracks, sprockets and rollers.

See it working

Ask to see the shredder running with material similar to yours. Watch how it feeds, how often it reverses and what the output looks like. Get the manuals and any CE documentation, and confirm ownership and that no finance is outstanding.

Where to find used slow speed shredders

Browse current used shredders for sale on Plant And Tractor Trader, along with the wider range of waste and recycling machinery. If you are building a line, look at screeners for after the shredder and material handlers for feeding it. Green waste operators may also want our guide to buying a used wood chipper, and metal recyclers can read about getting more value from metal scrap with a hammer mill. Sign up for stock alerts to hear when new shredders are listed.

Selling a shredder?

If you have a shredder or other recycling machinery to sell, you can advertise on Plant And Tractor Trader and reach buyers across the UK and Ireland. A single 8-week listing is £150 + VAT, or dealers can list all their stock on our unlimited listings plan for £100 + VAT a month.

Frequently asked questions

What is the difference between a slow speed and a high speed shredder?

A slow speed shredder uses low revs and high torque to tear material between toothed shafts, so it copes better with contaminants and makes less dust and noise. A high speed shredder or grinder uses hammers or knives at high revs, which can give a finer output but is more easily damaged by stones and metal.

Should I buy a single shaft or twin shaft shredder?

Choose a twin shaft machine if you need to break down bulky, mixed or dirty waste as a first stage. Choose a single shaft machine with a screen if you need a more consistent output size, for example for waste wood or plastics.

What wears out on a slow speed shredder?

The cutting teeth, discs, counter combs, screens and wear liners are the main wear parts. Shaft bearings, seals and the drive also wear over time, so check them carefully and ask when they were last replaced.

Need help finding a shredder?

Looking for a particular slow speed shredder? Send us a message on WhatsApp on 07470 093663 with what you need, and we will point you in the right direction.