Bosch 1-1/8 in Hex Clay Spade

Why I reached for this clay spade

Staring at a trench layout across hard-baked clay is a good test of your tool choices. Shovels bounce. Picks chip. A demolition hammer with the right spade does the grunt work. That’s what led me to the Bosch clay spade—simple, stout, and sized to move dirt efficiently without beating the operator senseless.

This is a 1-1/8 in hex shank spade with a 21 in overall length and a roughly 5-3/8 in cutting edge. On paper, that’s the classic formula for trenching through compacted soil and clay with a full-size demolition hammer. In practice, it has become my default bit for sod removal, shallow utilities, French drains, and footing cleanouts where a shovel would be slow and a pointed chisel would be tedious.

Setup and compatibility

The 1-1/8 in hex shank is a standard on larger demolition hammers, and it slots into my big hammer without drama. The hex profile keys positively, so there’s no rotation or slippage under load (a common annoyance with round-shank bits). If your tool uses SDS-Max or a 7/8 in hex system, this spade won’t fit—you’ll need the corresponding version. On some hammers, a retaining collar or clip is part of the system; as with any demo bit, check your chuck style before you buy.

At 21 in long, the spade sits in the Goldilocks zone: long enough to keep the hammer body out of the trench and give you a workable stance, short enough to remain controllable and not whip around when the tip bites.

In the ground: performance

Clay spades are about slicing and lifting, not gouging. The Bosch’s 5-3/8 in blade is wide enough to move material at a useful rate but not so wide that it constantly binds. Here’s how it handled common tasks for me:

• Trenching in heavy clay: I ran it at a shallow angle, letting the cutting edge undercut 2–3 in at a time. The steel profile feels stiff enough to transmit energy without flex. It shears dense clay cleanly when you keep the tool moving. In hardpan with gravel inclusions, it will bounce if you try to take too thick a bite; lighter passes keep progress steady.
• Sod removal: It shines here. Lay the blade nearly flat, zip under the root mat, and peel. The width is just right to roll manageable strips without leaving a jagged edge.
• Root crossing: For small roots (up to thumb-thick), it will slice with a controlled jab. For anything larger, I rotate to a narrower chisel or use a saw to avoid bruising the blade and my wrists.
• Backfill shaping and cleanup: The flat face makes it easy to square trench walls and level subgrade without constantly swapping bits.

A note on technique: let the hammer do the work. Keep the blade just off perpendicular to the soil, slide in, lift slightly to pry, then release and advance. If you set the edge too steeply, any clay spade will stall or ricochet, and you’ll fatigue quickly.

Ergonomics and control

A spade is only as friendly as its vibration and balance allow. With this one, the shorter 21 in length helps control. You’re closer to the work, can modulate angle changes precisely, and the bit doesn’t amplify the hammer’s oscillations as much as longer spades sometimes do. If you’re working all day, anti-vibration gloves and hearing protection are still musts—this is demolition-hammer territory—but I didn’t find the Bosch to aggravate vibration beyond what’s typical for a full-size setup.

The hex shank’s positive engagement also aids control: when you clock the spade to a specific orientation, it stays put, which matters when you’re cutting a straight trench wall and don’t want the blade to twist off line.

Steel, wear, and maintenance

Clay spades don’t need razor edges. In fact, a slightly blunt profile keeps them from diving erratically and reduces sticking in gummy soils. The Bosch arrives with a sensible factory grind—square leading face, eased corners, and a robust cross-section. After several days across mixed clay and compacted fill, my edge showed predictable rounding but no chips or mushrooming at the shank.

If you do decide to dress the edge, use a flap disc or belt grinder and keep the profile square and symmetrical; avoid over-thinning the lip. Heat buildup will soften the steel, so short, cool passes are better than production grinding. Because the blade is relatively wide, it sheds packed clay fairly well, but in wet conditions, I’ll still pause to tap the face clean to maintain efficient slicing.

Where it shines

• Clay and compacted soil trenching: The width-to-length balance makes steady, controlled progress without frequent stalls.
• Sod and turf removal: Clean, fast undercutting with minimal tearing.
• Trench finishing: Squaring edges and leveling bottoms is easier than with pointed or narrow chisels.
• General utility work: From shallow conduit trenches to landscape edging, it’s a versatile profile.

Where it falls short

• Large roots and rocky subsoil: This is not a root or rock chisel. In cobble or embedded stone, expect deflection. Swap to a narrower point when you hit obstruction, then return to the spade.
• Asphalt or masonry: It will bruise thin asphalt, but an asphalt cutter or a flat chisel is more effective and kinder to the spade.
• Deep/narrow trenches: If you’re cutting a narrow trench where every inch of width matters, a narrower spade may be a better match.

None of these are flaws so much as limitations of the form factor. Clay spades are purpose-built; use it for what it’s good at and it’s excellent.

Alternatives and pairings

If your hammer is SDS-Max, look for a similar clay spade in that interface. For 7/8 in hex hammers, the same advice applies. I like to keep this spade paired with:
- A pointed chisel for breaking hardpan and cobbles
- A 3 in or 4 in wide chisel for tighter trenches
- An asphalt cutter if I’m crossing driveways

That trio covers 90% of soil and light demo workflows without changing tools mid-task.

Durability and value

Bosch has a solid track record on heavy-use steel, and this spade fits the pattern. The shank tolerances are clean, the heat treat feels right (tough without feeling brittle), and the welds and transitions are smooth with no stress risers that might invite cracks. After repeated insertion cycles and plenty of lateral prying, I saw no damage to the shank flats or deformation at the collar area.

Value is always relative to your hammer system and how often you trench. For a dedicated clay spade with a standard 1-1/8 in hex shank, the balance of performance and expected lifespan is compelling. If you’re a landscaper, plumber, or general contractor who opens ground regularly, this is a consumable that should last well through multiple jobsites if used appropriately.

Practical tips for best results

• Work in shallow passes. Undercut, pry, clear, repeat. You’ll move more dirt with less vibration.
• Clock the blade. Align the flat with your trench wall and lock it in; hex shanks make orientation reliable.
• Keep it clean. Knock off sticky clay periodically to maintain a consistent bite.
• Don’t oversharpen. A slight bluntness improves control and reduces binding.
• Respect obstructions. Switch bits for rocks and thick roots to protect the edge and your wrists.

Final recommendation

I recommend the Bosch clay spade for anyone running a 1-1/8 in hex demolition hammer who needs a reliable, efficient bit for trenching and sod removal. The 21 in length offers good control and reach, the 5-3/8 in blade moves material at a satisfying pace without constant binding, and the hex shank engagement keeps orientation solid under load. It’s not a universal demolition bit—and it shouldn’t be. Used within its intended lane—clay, compacted soil, and turf—it’s a straightforward, durable performer that makes ground work faster, cleaner, and less punishing.