What a jointer does
The board slides face down along two long tables with a cutterhead between them. The infeed table sits lower than the outfeed table by the depth of cut, so each pass shaves the high spots off and the new surface rides on the outfeed table, staying straight. JET's manual gives the purpose plainly: surfacing produces one flat face, and the other side 'can then be milled to precise, final dimensions on a thickness planer'. With that face held against the fence, the next pass squares an edge, which JET calls the necessary step before ripping to width on a table saw. A woodworking jointer does not set thickness and does not make two faces parallel — see jointer vs planer.
Do not confuse it with a joiner: biscuit and plate joiners cut slots for joints, and a joiner is a trade. A jointer plane is a long hand plane, covered in the hand plane guide. In Britain a jointer is often called a surface planer.
Tables, fence and guard
- Infeed table — raised or lowered to set the depth of cut; Powermatic's 60C has a stop at 1/8 in.
- Outfeed table — level with the knives at the top of their arc. Powermatic sets it with a straightedge and calls it a one-time calibration, repeated after changing knives.
- Fence — square to the tables for edges, tilting to 45° in or out for bevels; JET checks it with a combination square.
- Guard — covers the cutterhead and swings aside as the board passes. OSHA's rule for workplaces requires an automatic guard covering the head on the working side of the fence and another behind it.
Sizes, by maker
| Machine | Width × depth | Cutterhead | Table length | Power as stated |
|---|---|---|---|---|
| JET JJ-6HHBT (benchtop) | 6 × 1/8 in | 14 inserts in 2 spiral rows, 10,000 rpm | 28-5/8 in | Brushed DC, 115 V, 15 A |
| Grizzly G0945 / G0946 (benchtop) | 6 × 1/8 in | Straight knives or spiral, 11,000 rpm | 30 in | 1-1/2 HP, 120 V, 10 A |
| Grizzly G0947 (benchtop) | 8 × 1/8 in | Spiral, 16 inserts, 11,000 rpm | 34 in | 1-1/2 HP, 120 V, 10 A |
| Powermatic 54A / 54HH | 6 × 1/8 in | 3 knives or 40 inserts, 6,000 rpm | 66 in | 1 HP, 1-phase, 115/230 V |
| Powermatic 60C / 60HH | 8 × 1/8 in | 3 knives or 54 inserts, 7,000 rpm | 73 in | 2 HP, 1-phase, 230 V |
| Powermatic 1285 | 11-3/4 × 1/8 in | 3 knives or 42 + 2 inserts, 5,000 rpm | 84 in | 3 HP, 1-phase 230 V or 3-phase 230/460 V |
Each figure is the maker's own. Width limits the widest face a board can have flattened; table length governs how long a board the tables carry — Powermatic asks for an assistant or support once a board is more than twice the table length. Knife and insert heads are compared in planer knives and inserts.
Equipment notePaid link
6-in benchtop helical jointer
JET JJ-6HHBT
The benchtop jointer in the table above: JET gives the JJ-6HHBT a 6 in width and a 28-5/8 in table, and requires it bolted to a firm bench.
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Minimum stock and depth, which differ
| Machine | Shortest | Thinnest | Deepest cut |
|---|---|---|---|
| JET JJ-6HHBT | 8 in for jointing; 12 in for surfacing without a special fixture | 1/4 in; 3/8 in for surfacing without a fixture | 1/8 in; about 1/16 in recommended |
| Grizzly G0945–G0947 | 10 in | 1/2 in | 1/8 in |
| Powermatic 54A / 54HH | 8 in | 1/4 in | 1/8 in (1/2 in when rabbeting, 54A) |
| Powermatic 60C / 60HH | 8 in | 1/4 in | 1/8 in; bevels no deeper than 1/16 in |
JET's manual gives both figures for the same machine; follow the stricter one. Push blocks are required below set sizes — JET and Powermatic: surfacing stock under 12 in long, 3 in wide or 3 in thick — and hands stay at least 3 in from the cutterhead.
Rabbeting only where the manual allows it
Some jointers cut rabbets on a ledge at the end of the cutterhead; many cannot. Powermatic's straight-knife 54A and 60C rate 1/2 in, but rabbeting is 'not applicable' on their insert-head twins, and on both machines the procedure requires taking the cutterhead guard off — which BenchRoot does not recommend and does not describe. The 12 in 1285 carries two rabbeting inserts for 3/4 in. JET's benchtop manual describes no rabbeting at all. If the manual does not cover it, the machine is not for it; the router guide and the dado blade guide cover other ways to cut one.
Dust and power
Benchtop jointers take a small hose — 2-3/8 in on the JET, sized for a 2-1/2 in hose, and 2-1/2 or 4 in on the Grizzlys — while floor machines have 4 in ports. A port's size is not a collector rating; Powermatic states a minimum of 800 CFM for the 1285 only. Power is stated in different units by different makers: JET gives amps for a brushed DC motor, Grizzly horsepower and amps, Powermatic horsepower, phase and voltage. A 230 V or three-phase machine needs the supply on its nameplate, wired as its manual says.
Rules the manuals share
- Keep the guard in place and working; disconnect power before any adjustment.
- Feed with the grain; Grizzly describes it as the grain running down and toward you, seen from the edge.
- Put a cupped or bowed board concave side down and take light cuts.
- Never press down directly over the cutterhead, never pass a hand over it, and never pull the board back toward the infeed.
- Use push blocks for short, thin or narrow stock; keep hands at least 3 in from the cutterhead.
- Support boards longer than twice the table length.
Before using a jointer
- Outfeed table level with the knives, checked with a straightedge
- Fence square to the table, or set to the bevel
- Guard covering the cutterhead and springing back
- Depth no more than the maker's limit; about 1/16 in for surfacing
- Stock above the manual's minimum, free of nails and loose knots
- Push blocks at hand; supports for long boards
Step-by-step use is in how to use a jointer. Choosing one: a jointer of any size, a benchtop jointer or a combination jointer-planer; the overview of this woodworking jointer and planer cluster is the planer guide. Reading which way the grain runs is in the wood grain guide.
Sources
Every figure is the named maker's for its own machine. JET's manual gives two different minimums for the same benchtop jointer, and both are shown. Powermatic writes that an outfeed table set too high curves the cut in one manual and tapers it in another; both describe the same fault. Cutterhead names follow each maker: Powermatic says helical, Grizzly's benchtop manual and JET's say spiral. No machine was tested.
- 1.
Operating Instructions and Parts Manual, 6-inch Bench Top Jointer, Model JJ-6HHBT (M-718600, edition 3). JET, 2025.
Used for: The JJ-6HHBT benchtop jointer: brushed DC motor, 115 V, 60 Hz, 15 A; 10,000 rpm; '14 inserts in 2 spiral rows'; 1/8 in deepest cut; 6 in wide; 28-5/8 in table; 71 lb; no jointing of stock shorter than 8 in, narrower than 3/4 in or thinner than 1/4 in, yet no surfacing of pieces shorter than 12 in or thinner than 3/8 in without a special holding fixture; push blocks; hands no closer than 3 in; the outfeed table level with the knives at their highest point; surfacing to make one flat face before a planer; edge jointing as the step before ripping.
- 2.
Operating Instructions and Parts Manual, 6-inch Woodworking Jointer, Models 54A and 54HH (M-1791279DX, edition 07). Powermatic, 2025.
Used for: The 54A and 54HH: 6 in by 1/8 in, 6,000 rpm, three knives giving 18,000 cuts per minute or 40 four-sided inserts in six rows; 1 HP, single-phase 115/230 V, pre-wired 115 V; 66 in tables; 1/2 in rabbeting on the 54A, not applicable on the 54HH, and rabbeting requiring the guard's removal; an outfeed table too high giving a curved surface and too low a gouge at the end.
- 3.
Operating Instructions and Parts Manual, 8-inch Jointer, Models 60C and 60HH (M-1610084, edition 8). Powermatic, 2025.
Used for: The 60C and 60HH: 8 in by 1/8 in, 7,000 rpm, 21,000 knife cuts per minute or 54 inserts; 2 HP, single-phase 230 V; 73 in tables; a depth stop at 1/8 in; the outfeed table set with a straightedge, too high giving a tapered surface; stock longer than twice the table length supported; the guard used except when rabbeting.
- 4.
Operating Instructions and Parts Manual, 12-inch Jointer, Models 1285 and 1285T (M-0460216, edition 7). Powermatic, 2023.
Used for: The 1285: 11-3/4 in by 1/8 in, 5,000 rpm, 3/4 in rabbeting, three knives or 42 inserts plus 2 rabbeting inserts; 3 HP single-phase 230 V or three-phase 230/460 V; 84 in tables; at least 800 CFM of dust collection; 762 lb.
- 5.
Model G0945/G0946/G0947 6" & 8" Benchtop Jointers owner's manual (for models manufactured since 12/23). Grizzly Industrial, 2023.
Used for: The G0945, G0946 and G0947 benchtop jointers: 6 or 8 in, 1/8 in, 11,000 rpm, straight knives or a 'spiral' head; 1-1/2 HP universal motor, 120 V, 10 A; no cuts on pieces shorter than 10 in; never run with guards removed except when rabbeting; an outfeed table too high or too low raising the risk of kickback.
- 6.
29 CFR 1910.213, Woodworking machinery requirements: (j) jointers, (n) planing machines, (s)(12) jointer knives and push sticks. U.S. Occupational Safety and Health Administration.
Used for: For workplaces: a hand-fed jointer's automatic guard covering the cutterhead on the working side of the fence and adjusting itself to the stock; a guard behind the fence; a rear-table clearance of no more than 1/8 in; knives projecting no more than 1/8 in; push sticks or blocks provided.
About this guide
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