Bosch 25-Piece 1/8" x 4" BlueGranite Turbo Carbide Hammer Drill Bits

Why I Reached for These Bits

I stocked this 25-pack of BlueGranite Turbo 1/8-inch bits for a week of light electrical and hardware installs in block, brick, and cured concrete. The mandate was simple: lots of small, clean holes for clips, anchors, and pilot work, ideally without babysitting a single fragile bit all day. I ran them in both a compact hammer drill and an impact driver with a quick-change chuck, switching depending on the access and how stubborn the base material was. By the end of the week, a few patterns emerged—speed and start accuracy were strong points, as was the convenience of the hex shank in tight or overhead work.

Design and Build

These bits sit in a useful niche: carbide-tipped masonry cutters with a 1/4-inch hex that locks into impact drivers or hammer drills. The head geometry is a four-grind profile with a multi-grind centering tip. In practice, that nose shape helps the bit “grab” on slick surfaces—painted block, glazed brick, and hard troweled concrete—where plain chisel-tip masonry bits like to skate. The flutes are milled with deep spirals for dust evacuation. On a slender 1/8-inch bit, flute design matters; there’s not much cross-section to both cut and carry spoil, so efficient chip flow reduces heat, binding, and the temptation to push too hard.

The overall length is compact and the usable flute is around two inches. That suits small anchors, cable and conduit clips, and pilot holes for light-duty fasteners. If you need deep embedment, this isn’t the right size anyway; for what 1/8-inch is typically asked to do, the length is appropriate and easy to control.

Setup and Compatibility

I tested in two configurations:

• Compact hammer drill, percussion engaged
• 18V impact driver with quick-change hex

The hex shank is the hero for the driver setup. Swapping from drilling to driving in a single tool, especially on ladders or lifts, saves time and keeps the footprint light. In a hammer drill, the bits seat without fuss and run true; I saw no wobble or poor fit.

One note on impact drivers: they’ll turn these bits in masonry just fine, and the bits are clearly designed for that abuse. But in dense concrete, a hammer drill’s true percussion still cuts faster and cooler. I generally reached for the driver where convenience and access were the priority, and the hammer drill when I wanted a stack of holes methodically and quickly.

Drilling Performance

Start accuracy is where these bits immediately impressed me. On painted CMU, I could place a hole on a pencil mark and trust the tip to stay put. On glazed brick faces, a light pilot tap with a punch plus the centering geometry prevented wandering that I typically fight with budget masonry bits.

Cutting speed is above average for this class. In 20-year-old slab and standard block, a clean 1/8-inch hole to a typical clip depth was quick and consistent with the hammer drill in percussion mode. In an impact driver, the pace was respectable, especially in block and mortar joints, and notably better than straight-shank masonry bits not designed for impact use.

Dust evacuation through the U-flutes is effective for the bit size. I still prefer to peck-drill—advance 3/4 inch, back out to clear—but the flutes move spoil reliably so you can maintain steady pressure. Overheating wasn’t an issue when I followed that rhythm and avoided burying the bit continuously in dense concrete.

Breakthrough was mostly clean. For surface-critical faces like brick veneer, easing up in the last 1/8-inch reduced spalling on the back side. These are still small masonry bits; a gentle finish helps keep the hole edges intact.

Durability and Wear

Longevity is the hardest test for a 1/8-inch masonry bit. The shank is thin, heat builds quickly in dense material, and even a minor bind can snap a lesser bit. The BlueGranite Turbos fared well. I could get multiple dozen holes in block and mortar on a single bit, and a fair number in cured concrete before the edges dulled to “slow but serviceable.” I didn’t snap any in normal use, which I attribute to both the flute clearing and the robust head. When I forced the issue—hard side-load on a misaligned hole—the bit protested but didn’t immediately shear, which is better than average for this diameter.

As always: hit embedded metal and all bets are off. If you’d expect rebar or tie wire, scan first; a 1/8-inch carbide tip is not the tool to plow through steel.

Where They Fit Best

• Electrical and low-voltage fasteners: cable clips, strap anchors, light-duty anchors that spec a 1/8-inch pilot.
• Trim and hardware on masonry: small brackets, conduit clamps, and tap-ins.
• Overhead work and ladder work: the hex shank in an impact driver makes for a quick, compact setup when maneuvering matters.
• Pilot holes in brittle masonry prior to step-drilling: reduce surface spall and ensure placement before moving up to a larger diameter.

Limitations and Tradeoffs

• Size-specific: this is a 25-pack of 1/8-inch. Great for volume, but if you need a range of diameters, you’ll want a mixed set alongside.
• Not a substitute for SDS-plus: for heavy anchor schedules, deep embedments, or large holes in hard concrete, step into SDS territory.
• Technique sensitive: as with all thin masonry bits, aggressive side pressure or continuous buried drilling in hard aggregate shortens life. Pecking and modest feed pay dividends.
• Depth: with roughly two inches of usable flute, you’re operating in the shallow-hole category. Most use cases at 1/8 inch fit that, but it’s worth noting.

Practical Tips

• Let percussion do the work. In a hammer drill, steady pressure is faster than force. In an impact driver, use moderate speed and peck to keep the bit cool.
• Mark and punch slick surfaces. A small dimple plus the centering tip nearly eliminates skating on painted or glazed faces.
• Vacuum as you go. Clearing dust improves speed, keeps the hole true, and reduces wear on the cutting edges.
• Back off before breakthrough. Light pressure at the end preserves the backside of brick and block.
• If you feel grabby aggregate, withdraw, clear, and re-approach. Forcing through a bind is the quickest way to sacrifice a small-diameter bit.

Value for Crews and DIY

The 25-pack approach makes sense. This is a consumable size, and keeping a box on the truck means fewer mid-job delays hunting for a fresh bit. Performance and consistency were reliable across the pack, which is not a given with cheaper bulk masonry bits. If you run a lot of small holes in masonry week in and week out, the combination of speed, start accuracy, and the convenience of the hex shank justifies having these on hand.

Recommendation

I recommend the BlueGranite Turbo 1/8-inch bits for anyone who routinely drills small holes in masonry, block, or concrete and wants the flexibility to run them in either a hammer drill or an impact driver. They start accurately on tough surfaces, cut faster than standard chisel-tip masonry bits, clear dust well for their size, and hold up respectably under real jobsite use. The 25-pack format matches how this diameter gets used—often, and sometimes abusively—so you can keep moving without nursing a single bit through the day. If your work leans heavy-duty, deep, or oversized, they’re not a replacement for SDS-plus; but for high-volume small holes, these have become a dependable staple in my kit.