Woodmaxx WM-8M vs WM-8H
Both are 8-inch PTO chippers with a 19 HP minimum. Both are imported. The WM-8M ($3,690) uses a single mechanical roller. The WM-8H ($4,095) uses dual hydraulic rollers with reverse. That $405 gap buys you a fundamentally better feeding system — here's exactly what changes.
The Woodmaxx WM-8M and WM-8H are the two most commonly confused products in the Woodmaxx lineup. Both are 8-inch PTO chippers. Both require 19 HP minimum. Both are imported (not USA-made). The WM-8M vs WM 8M vs WM8M search brings people here looking for the same thing: which one is worth the extra $405?
The answer is almost always the WM-8H — but it depends entirely on the type of material you chip. If you only ever push clean, straight branches of uniform diameter into the hopper, the WM-8M is fine. The moment you try forked branches, vine-covered wood, or anything with a curve, the dual hydraulic rollers of the WM-8H stop being optional.
Important note on availability: The WM-8M is currently on waitlist at Woodmaxx. If you need a chipper soon, the WM-8H ships in-stock within 5 business days. Factor lead time into your decision.
Side by side.
| Spec | WoodmaxxWM-8M | WoodmaxxWM-8H |
|---|---|---|
| Brand | Woodmaxx | Woodmaxx |
| Power | pto | pto |
| Max branch | 8" | 8" |
| HP requirement | 19–50 HP | 19–50 HP |
| Feed | Self-feeding | Hydraulic |
| Weight | 950 lb | 990 lb |
| Warranty | 3 yr | 3 yr |
| Price | $3,690 | $4,095 |
The real difference: how the feed system works
The WM-8M uses a single mechanical roller. It’s spring-loaded and pulls material in using friction alone. Once a branch is in the throat, the roller drives it forward at a fixed rate. There’s no way to slow the feed, no reverse, and no second roller to compensate when material tries to rotate or kick.
The WM-8H uses dual counter-rotating hydraulic infeed rollers, powered by a self-contained hydraulic pump and a 38-liter (7 gallon) ISO-46 reservoir — no tractor hydraulics needed. The two rollers work together to grip material from both sides, preventing rotation on forked branches. Feed speed is adjustable from 0 to 75 ft/min. The safety bar reverses both rollers instantly if you need to back material out.
In practice: feed a forked 6-inch branch into the WM-8M and it can twist, kick, or stall. Feed the same branch into the WM-8H and the dual rollers clamp it from both sides and pull it through. This isn’t a minor comfort upgrade — it’s a fundamental operational difference.
HP requirement: both need 19 HP minimum
One of the most-searched questions is whether the WM-8H needs more tractor HP than the WM-8M. It does not. Both require 19 HP minimum PTO(the absolute spec sheet minimum is 15 HP). At 19 HP, both machines chip 4-inch hardwood and 6-inch softwood. Full 8-inch capacity on either machine requires 50 HP. The WM-8H’s hydraulic system draws 2–3 HP from the PTO to run the pump, but Woodmaxx rates both machines identically at 19 HP minimum.
Weight and specs: nearly identical
The WM-8M ships at 950 lb; the WM-8H ships at 990 lb (the 40 lb difference is primarily the hydraulic fluid reservoir). Both use the same 200 lb, 24-inch dynamically balanced flywheel. Both have a 3-year warranty. Both use 2 reversible USA-made A8 tool steel knives. Both accept Cat 1 and Cat 2 three-point hitches and are Cat-1 quick-hitch compatible. The core chipper housing is the same — Woodmaxx builds both on the same platform.
Maintenance comparison: hydraulic vs mechanical
The WM-8M’s mechanical feed requires less maintenance — no hydraulic fluid to check and change, no pump to service, no hydraulic hoses to inspect. Fewer moving parts means fewer things that can fail.
The WM-8H requires 7 gallons of ISO-46 hydraulic fluid (included with purchase). The fluid should be checked before each use and changed periodically per the manual. The hydraulic pump and hoses add inspection points. That said, Woodmaxx uses JIC fittings (5,000 psi rated) and a nylon-wrapped hose configuration — the hydraulic system is designed for durability, not convenience. The additional maintenance is real but light.
Price gap: $405 for the feed system upgrade
The WM-8M lists at $3,690; the WM-8H at $4,095 — a $405 difference. For context: a single service call for a jammed chipper typically runs $150–$300 in labor plus parts. If the WM-8M’s mechanical feed jams even twice over its lifetime and you need service both times, the WM-8H would have been cheaper. That said, for owners who chip exclusively clean material, the mechanical feed is reliable and the savings are real.
Frequently asked questions
- What is the difference between the Woodmaxx WM-8M and WM-8H?
- Both are 8-inch PTO chippers with a 19 HP minimum. The WM-8M ($3,690) uses a single mechanical infeed roller — it pulls material in at a fixed rate with no reverse. The WM-8H ($4,095) uses dual hydraulic infeed rollers with adjustable speed (0–75 ft/min) and a reverse function. The WM-8H handles forked and crooked material; the WM-8M can stall on it.
- Is the WM-8M available to buy?
- As of June 2026, the WM-8M is on waitlist at Woodmaxx.com — it shows out of stock with a join-waitlist form. The WM-8H is in stock and ships within 5 business days. Verify availability at woodmaxx.com before making a decision based on price.
- What tractor HP do I need for the WM-8M or WM-8H?
- Both models require 19 HP minimum PTO. At 19 HP you'll chip 4-inch hardwood and 6-inch softwood; full 8-inch capacity needs 50 HP. The WM-8M is currently on waitlist — check availability before ordering.
- Does the WM-8H require tractor hydraulics?
- No. The WM-8H uses a self-contained hydraulic system with its own 7-gallon reservoir. No tractor hydraulic connection is required. This is a major advantage over chippers that tap the tractor hydraulic circuit.
- Can the WM-8H reverse its feed rollers?
- Yes. The WM-8H has a hydraulic auto-feed stop bar at the top of the infeed bin that reverses both infeed rollers when activated. This lets you back material out of the chipper without reaching in. The WM-8M has no reverse function.
- Are the WM-8M and WM-8H USA made?
- No. Both the WM-8M and WM-8H are imported. The WM-8H spec sheet explicitly states 'Imported from overseas.' If USA manufacture matters, look at the Woodmaxx MX-8800 ($6,225) or MX-9900 ($7,350), both made in Buffalo, NY.