Best hole saw kits: bi-metal sets picked by size range, cut depth and arbor

01What should a hole saw kit have?

A hole saw kit should have bi-metal saws in the sizes you actually cut, enough cutting depth for the material, arbors that fit every saw in the box, and pilot bits. A hole saw is a cup-shaped saw that removes only a ring of material and leaves a plug, and it mounts on an arbor that carries a pilot drill. The kit's value is in how well those parts work together.

Tooth material: bi-metal for mixed jobs

Bi-metal hole saws have HSS or cobalt-HSS teeth on a tougher backing, and they cut metals, including stainless sheet, as well as wood and plastics. Starrett lists carbide-tipped hole saws for non-metallics such as wood, MDF, plasterboard and tile, where it says they cut faster than bi-metal, and diamond-grit hole saws for glass, porcelain and stone. All five picks are bi-metal, which makes them the general kits; carbide and diamond saws are specialist add-ons.

Cutting depth: standard or deep cut

Standard bi-metal hole saws cut about 1-5/8 in deep. Starrett's deep-cut bi-metal saws reach about 2 in and need arbors with an extended pilot drill. Depth decides whether you can cut through a door, a joist or a stud in one pass or have to finish from the other side.

Arbors: the part most kits are judged on

Small hole saws use a small-thread arbor with a 1/2–20 thread; larger ones use a large-thread arbor, which Milwaukee gives as 5/8–18. A kit that spans both groups therefore needs two arbors or an adapter. The arbor shank must also suit your chuck: 3/8 in hex-shank arbors fit drills with a chuck of that size or larger, while the larger hex shank found in some kits needs a 1/2 in chuck. Milwaukee's own arbor set uses a 1/4 in pilot bit. The hole saw size chart lists which hole each common fitting needs.

02What rules a hole saw kit out before you compare sizes?

A kit is ruled out if its arbor shank is too big for your chuck, if it lacks the sizes your fittings need, or if it is the wrong tooth type for the material. Check these before piece count, because a large kit that misses your key size is still the wrong kit.

• Chuck size. A 1/2 in chuck accepts every arbor in these kits. A smaller chuck limits you to the smaller hex arbors. The common drills in the table below all list a chuck of that size; compact drills may not. Our guide to drill chuck sizes covers the difference.
• Key sizes. Door locksets need a 2-1/8 in bore through the door face and a 1 in hole in the edge. Electrical knockouts are larger than their trade names suggest: Klein gives the knockout for the smallest common conduit trade size as 0.875 in. A kit's size range only tells you its smallest and largest saw, so read the contents list to confirm the exact sizes are included.
• Tooth type. Bi-metal for mixed work; diamond for tile, porcelain or glass, which none of these kits covers.

A common mistake is to assume any arbor fits any hole saw. Small saws need the small-thread arbor and larger saws the large-thread arbor, so a lone arbor bought separately may only fit half a kit.

04How do the hole saw kits differ?

The kits differ most in size range and arbor system, then in cutting depth. Tooth material is the same family across all five, so the choice comes down to which holes you cut and which drill drives the saw.

Milwaukee 49-22-4185 vs Bosch HBT15M: range or impact-driver use?

Milwaukee's kit reaches 3/4 to 4-3/4 in, well past Bosch's 3/4 to 3 in, and includes three arbors. Bosch's set is the only pick whose maker lists impact drivers alongside drill/drivers, and it states an M42 alloy in its teeth. Pick Milwaukee for the widest spread of holes; pick Bosch if your main cordless tool is an impact driver and the sizes fit your work. Keep impact-driver hole sawing to light work: Milwaukee rates its own SHOCKWAVE impact hole saws for plastics and thin-gauge metal up to 1/8 in thick, so check the materials Bosch lists before taking the HBT15M into thicker stock.

Diablo DHS14SGP vs DeWalt D180005: depth or a standard arbor?

Diablo's saws are 2-3/8 in long, the deepest figure published by any maker here, and they eject plugs without tools. The trade-off is Diablo's own Snap-Lock Plus mandrel. DeWalt's kit uses conventional small and large hex arbors and covers 3/4 to 2-1/2 in. Both suit framing work; Diablo saves passes in thick stock, and DeWalt keeps you on a standard arbor format.

Where does the Lenox kit fit?

Lenox sells the 1786647 for electricians and plumbers and says it fits quick-change and standard arbors without adapters. Lenox's size range could not be confirmed from a page we were able to verify, so it is not given here. Compare the box contents with the sizes your fittings need before buying.

05When do you need a hole saw extension?

You need a hole saw extension when the drill body cannot get close enough to the surface you are cutting, for example inside a cabinet, through a stack of joists or behind an obstruction. The extension is a bar that fits between the chuck and the arbor; none of the five kits above includes one, so it is a separate purchase. Milwaukee sells its QUIK-LOK extensions in 5-1/2, 6, 12, 18, 24 in lengths, with a choice of two hex shank sizes, and its catalogue says they fit all major brands. Starrett's extensions are 300 mm bars, one for half-inch chucks and one for three-eighths-inch chucks.

Match the extension's shank to your chuck in the same way as the arbor: the larger hex shank needs a half-inch chuck. An extension adds reach, not cutting depth; the cup still stops at its own depth, so a thick beam still needs a deep-cut saw or a cut from both sides. A long bar also magnifies any wobble, so start the cut slowly and keep the drill in line with the bar.

06How slowly should the larger saws in these kits run?

A hole saw should run slower as it gets bigger and as the material gets harder. Starrett's chart, reproduced below, gives speed bands by diameter for mild steel, stainless, cast iron, non-ferrous metals and wood. Large saws in stainless run at a small fraction of the speed of small saws in wood. A drill's top speed is far above these bands for the larger sizes, so use low gear and let the teeth cut rather than pressing hard. In metal, a little cutting oil helps the teeth, in line with Starrett's advice to lubricate when drilling metal.

Hole sawing is also hard on the hands. UK HSE's hand-arm vibration guidance L140, in its second edition from 2019 and still the current one, gives a drill running a hole saw a recommended initial estimate of 10 m/s², twice its figure for a drill with a standard bit. The estimate is based on tools in use before 2015 and remains HSE's most recent figure of its kind. For a kit buyer it is a reason to keep the bi-metal teeth sharp, use the drill's side handle on the larger sizes, and cut a batch of large holes in short spells rather than one long session.

07When is a hole saw kit the wrong tool?

A hole saw kit is the wrong tool for small holes, for tile and glass, for flat-bottomed holes, and for cuts deeper than the saw. Each of these has a better accessory.

• Small holes. Below the smallest saw in the kit, a twist bit or step bit does the job. Stepped bits drill a range of sizes in sheet metal with one bit; see the stepped bits for sheet metal.
• Tile, porcelain and glass. Bi-metal teeth are not made for these. Diamond-grit hole saws cut them and must be cooled with water, and Starrett also lists carbide-tipped hole saws for ceramic tile. Swap the pilot too: Milwaukee says to use its carbide-tipped pilot bit with carbide-grit saws in tile, brick and other abrasive materials.
• Flat-bottomed or partial holes in wood. A hole saw cuts straight through and leaves a plug. For a hinge cup or a blind hole, a boring bit is the tool; our comparison of Forstner versus spade bits explains which to use.
• Material thicker than the saw. Cut until the pilot bit comes through, then finish from the other side using the pilot hole as a guide, or choose a deeper saw.
• Masonry. SDS rotary hammer core bits are a separate system; a bi-metal hole saw is not made for concrete.

08How do you match a kit to your holes?

List the holes you cut most often, then choose the kit whose contents include those exact sizes and whose arbors fit your chuck. A door installer needs the lockset bore; an electrician needs the knockout sizes in the table above; a plumber needs pass-through sizes for the pipe in use. Klein's knockout figures are a single-source reference, so confirm against your own fitting when the fit is tight.

The kits on this page cover the common sizes for each trade, but none publishes exactly the same list. For more comparisons, the accessory buying guides index lists every buyer guide, and the accessory finder shows the chuck size of your drill by model.

09Questions readers ask