What drill bit size do I need for a concrete screw?

The screw specifies it — usually close to its core diameter. A Tapcon 3/16" takes a 5/32" bit, a 1/4" takes a 3/16"; fischer's FBS II is named by the bit it needs (FBS II 8 → 8 mm). One size too big strips the thread; one too small snaps the screw. We make the full matched range Ø4–14 mm to a documented diameter tolerance.

Why does the exact diameter matter so much?

Because the screw's published pull-out and shear are tested at one hole size. A hole 0.3–0.5 mm oversize loses a large fraction of grip; undersize snaps the screw or won't let it drive. The bit is a tolerance part, not a commodity.

Do you make SDS-Plus and hex-shank versions?

Both. SDS-Plus for rotary hammers on high-volume anchoring; 1/4" hex / round shank for cordless drills and impact drivers on fit-out. Same ground-diameter spec on each.

Can you match bits to our concrete-screw brand?

Yes — that's the program. We grind to the exact Ø your screw's approval is tested at and document it per batch, either as the in-box bit or a standalone matched line under your label.

What's the carbide and body spec?

Controlled-atmosphere brazed virgin-powder YG8C carbide head (2-cutter standard, 4-cutter for reinforced concrete) on a hardened 40Cr / 42CrMo body. Diameter held to an h-class tolerance.

Concrete Screw Drill Bits Manufacturer & OEM — Matched-Diameter Carbide Bits for Tapcon, Würth & Hilti Screw Anchors

Concrete Screw Drill Bits Manufacturer & OEM — Matched-Diameter Carbide Bits for Tapcon, Würth & Hilti Screw Anchors | Zhonghuan

Factory-direct manufacturer of matched-diameter carbide drill bits for concrete screw anchors — Tapcon, Würth W-BS, Hilti HUS, DeWalt Screw-Bolt+, fischer FBS. SDS-Plus and hex/round shank, Ø4–14 mm, h-class diameter tolerance, controlled-atmosphere brazed YG8C carbide. OEM in-box bits and private-label matched-bit lines.

The Bit Diameter Is the Whole Load

A concrete screw — Tapcon, Würth W-BS, Hilti HUS, DeWalt Screw-Bolt+, fischer FBS or Simpson Titen — holds because its thread cuts into a precisely sized hole. The published pull-out and shear values assume one exact pilot diameter; the drill bit is the precision part that delivers it, not an afterthought. Zhonghuan manufactures the matched-diameter carbide masonry bits these screws are drilled with — SDS-Plus and hex/round shank — factory-direct for fastener brands, distributors and contractors.

Why Diameter Tolerance Is the Product

Drill one size too big and the thread never bites — the screw spins in the hole with a fraction of its rated grip. Drill one size too small and it snaps off or won't drive. There is no recovery from a wrong hole on a structural fixing. That makes the bit a tolerance part: we grind diameter to an h-class tolerance and hold it consistent batch to batch, so every hole is what the screw's datasheet assumes. A commodity bit that drifts +0.3 mm as it wears is a stripped anchor waiting to happen.

Matched to the Screw, Not Guessed

Every concrete screw specifies its pilot-bit diameter, usually close to the screw's core diameter so the thread engages sound concrete. A Tapcon 3/16" screw takes a 5/32" bit and a 1/4" takes a 3/16"; fischer's FBS II is named by the bit it needs (FBS II 8 → 8 mm). We make the full matched range — Ø4–14 mm / 5/32"–9/16" — so a buyer can source the exact bit for every screw in the program from one supplier, with the diameter documented per batch.

Shank Options for the Tool on Site

SDS-Plus — for rotary hammers, the fast choice for high-volume anchoring into concrete and masonry.
Hex (1/4") / round shank — for cordless drills and impact drivers, the way most light concrete screws go in on fit-out and service work.

Same ground-diameter spec on both shanks; the head is a controlled-atmosphere brazed carbide 2-cutter, or a 4-cutter where the work is reinforced concrete.

Specification, Stated Plainly

Diameter range: Ø4–14 mm (5/32"–9/16"), ground to h-class tolerance, documented per batch.
Head: controlled-atmosphere brazed virgin-powder YG8C carbide; 2-cutter standard, 4-cutter for reinforced concrete.
Shank: SDS-Plus to ISO 8035, or 1/4" hex / round for drill-driver use.
Body: hardened 40Cr / 42CrMo alloy steel.
Lengths: matched to common concrete-screw embedments, with deeper options for through-fixing.

OEM & Private-Label Programs

Two ways buyers source this from us: the in-box bit that ships with a concrete-screw SKU, ground to the diameter your screw's approval is tested at; or a standalone matched-bit line under your own brand, mapped to your screw range. Either way the diameter is the deliverable — documented, consistent, and tied to your pull-out data. Contact our team for the matched-bit chart against your screw program, diameter tolerances, MOQ and private-label options.