Spade bit sizes: the full chart, long bits, and set contents

A spade bit is the fast, crude wood-borer: a flat paddle with a center point, made for running cable and pipe through studs rather than for holes anyone will see. This page prints the actual size data, all of it from manufacturer pages and catalogs: the 17-size standard ladder with Bosch and Greenlee model numbers, the 16-inch long bits electricians use for wall plates, and the exact contents of the common sets, including the sizes every set skips ^{[1] [5]}. For how spade bits compare with Forstner bits and hole saws, see our wood boring bits compared page.

The standard size ladder: 17 sizes, two brands

Every row below is a size you can buy as an individual bit. Bosch's Daredevil line covers every 1/16 step from 1/4 through 1-1/2 inch at the standard 6-inch length; above 1 inch the ladder steps in 1/8 increments, which is why the count is 17 rather than 21 ^[1]. Greenlee's 33A covers the same span in 11 sizes, stepping in 1/8 above 1/4, at 6-1/4 inches overall ^{[5] [6]}.

Length notes, from Bosch's own release: the 6-inch length is standard across the ladder; 4-inch stubby versions exist in 3/8, 1/2, 5/8, 3/4, 1, 1-1/4, and 1-1/2 inch; and 6-inch and 12-inch extension shafts are sold separately ^[3]. Both brands use a 1/4-inch hex shank with a power groove, so every size here drops into the same quick-change chuck ^{[1] [6] [9]}. Greenlee's 33A paddles carry a hole in the center for pulling wire, the electrician's version of the tool ^[6].

Long spade bits: the 16-inch versions

Drilling through a wall plate or a doubled-up stud from inside a room is what 16-inch spade bits are for. Greenlee's 33L runs 10 sizes at 16 inches overall (406 mm), and the 1/16-step sizes are absent: the ladder is 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, 1, 1-1/8, 1-1/4, 1-1/2 ^{[5] [7]}. The 33L-1/2 product page prints the length directly: overall length 16.000 in (406.4 mm), 1/4-inch hex shank ^[8]. Bosch's extended-length line (DLSB models) covers 3/8 through 1 inch at the same 16-inch length ^{[4] [3]}.

Greenlee also makes the 34A self-feeding spade bit, sold from 3/8 through 1 inch plus a 34AR-6 set spanning 3/8 to 1. The 34A has a tapered self-feed tip and the same wire-pull hole, trading hole quality for less pushing force ^{[5] [7]}. We deliberately print no overall length for the 34A family: Greenlee's own catalog sheet and product pages disagree (6 versus 6-1/4 inches), so we won't pick one.

Set contents, and what each set skips

This is where buyers get surprised: the set in the drawer is not the ladder above. Three widely stocked sets, contents verbatim from manufacturer and dealer listings:

Read the skip column before buying a bigger set. The Bosch 13-piece looks complete and is not: if you need a 7/16-inch hole for a stub tenon or a 13/16 clearing hole, that bit is an individual purchase, because no common set carries the odd 1/16 sizes ^{[1] [2]}. At the top end, 1-1/8 through 1-1/2 exist as individual bits from both Bosch and Greenlee but appear in almost no set, so a thick cable loom through a plate usually means buying the single bit ^{[1] [5]}.

Speed: maximum RPM by diameter

Spade bits remove a lot of wood per revolution, and the safe speed falls as the paddle gets wider. The bands below come from published drill-speed charts; Bosch independently prints a 1500 RPM maximum right on the shank of its Daredevil bits, which corroborates the top of the range ^{[11] [12]}. No single industry standard governs these numbers, so treat them as ceilings and let burn marks tell you to slow down.

Two speed-chart publishers print identical spade tables, which is why we count them as one source family and cite the PDF original only ^[11]. For speeds across every other bit type and material, see the drill speed chart.

Choosing without overbuying

Most holes drilled with spade bits are cable and pipe clearings through framing, and 3/8 through 1 inch covers nearly all of them, which is exactly what the common 6-piece sets carry ^{[9] [10]}. Buy the set that matches your work, then fill gaps with individual bits using the ladder table above rather than assuming the next set up closes them. If the hole will be seen, or needs a flat bottom, a spade bit is the wrong family entirely; the trade-offs are on our wood boring bits compared page, and the clean-hole alternatives are the Forstner bit sizes and hole saw sizes charts. For the pilot holes that precede screws in the same framing, see the pilot hole chart; for hiding those holes with dowels, the plug cutter sizes page.

Related pages

• Wood boring bits compared: spade vs Forstner vs hole saw, with the RPM ceilings
• Drill bits by material: which bit family for wood, metal, concrete, tile
• Drill speed chart: RPM by diameter and material across bit types
• Pilot hole chart: screw pilot sizes before any boring
• Plug cutter sizes: cutting the dowels that hide these holes

Sources

1. Bosch, Daredevil Standard Spade Bits product category (all 17 DSB models with diameter, total length 4 and 6 in, and 1/4 in shank; DSB1015 1-1/8 x 6, DSB1017 1-1/4 x 6, DSB1021 1-1/2 x 6): boschtools.com
2. Bosch, Daredevil Spade Bit Sets category (DSB5013P 13-piece set with pouch, verbatim contents 1/4 through 1-1/2 in): boschtools.com
3. Bosch press release, Daredevil spade bit launch (length structure: 6 in standard sizes, 4 in stubby sizes 3/8 through 1-1/2, 16 in extended sizes 3/8 through 1, 6 and 12 in extension shafts): pressroom.boschtools.com
4. Bosch, Daredevil Extended Length Spade Bits category (DLSB1003 through DLSB1013, six diameters 3/8 to 1 in, total length 16 in): boschtools.com
5. Greenlee, Standard Spade Bits catalog sheet MA-4726 (33A ordering list 1/4 through 1-1/2, length of bits 33A 6-1/4 in / 159 mm, 33L 16 in / 406 mm, 34A 6 in / 152 mm; 33L ordering list; 34A list including 34AR-6 set 3/8 to 1): tradeservice.com mirror
6. Greenlee, 33A-1-1/2 1-1/2 inch Spade Bit product page (6-1/4 in / 158.8 mm overall length, 1/4 in hex shank, wire-pull hole in paddle): greenlee.com
7. Greenlee, Spade Bits category (33A, 33L, and 34A listings; 34AR-6 set 3/8 to 1 in): greenlee.com
8. Greenlee, 33L-1/2 1/2 inch Long Spade Bit product page (overall length 16.000 in / 406.4 mm, shank 1/4 in): greenlee.com
9. Coastal Tool, Irwin 88886 6-piece Speedbor set listing (standard equipment 3/8, 1/2, 5/8, 3/4, 7/8, 1 in; 1/4 in hex shank; 6 in length): coastaltool.com
10. Sutherlands, IRWIN 88886 woodboring spade bit set listing (same six sizes, all 6 in standard length): sutherlands.com
11. Carbide Processors, recommended operating speeds PDF (spade bits: 1/4 to 1/2 in 2000/1500 RPM, 5/8 to 1 in 1750/1500, 1-1/8 to 1-1/2 in 1500/1000, softwood/hardwood): carbideprocessors.com
12. HomeFixated, Bosch Daredevil spade bit hands-on review (photo and caption: recommended maximum speed 1,500 RPM printed on the shank): homefixated.com
13. Pro Tool Reviews, Bosch Daredevil spade bits review (17 blade sizes 1/4 to 1-1/2 in; 13-piece kit contents matching the first-party list): protoolreviews.com