410 Stainless Steel Concrete Screws

Medium-duty concrete screws in 410 stainless steel for exterior and high-moisture fastening. Builders Stainless stocks both the Simpson Strong-Tie Titen® and the DeWalt Crete-Flex® and UltraCon® SS4 lines, in flat head and hex head, for anchoring into concrete, brick, grout-filled CMU and hollow block. Each screw cuts its own threads as it drives — no shield, plug or expansion sleeve — and can be backed out and reinstalled if a fixture needs to come off.

Flat Head or Hex Head: Which Should You Use?

Choose the flat head when the fastener needs to sit flush or below the surface — countersunk into wood, trim, plates, or anywhere a protruding head would interfere. Choose the hex head when you want maximum driving torque and don't need a flush finish, such as ledgers, brackets, strapping and general structural attachment; the washer face seats against the fixture. Hole preparation is identical for both. The drive and drill bit, however, depend on the product line — see the table below.

Diameters, Drives and Drill Bits

These lines do not share one drill bit size. Match the bit to the specific part you are installing, not to the screw diameter.

Diameter & length	Head	Product line	Drive	Carbide bit	Code listing
3/16", 1 3/4"–3 1/4"	Flat	DeWalt Crete-Flex® SS4	T25 star	5/32"	Miami-Dade NOA
1/4", 1 1/4"–4"	Flat	Simpson Strong-Tie Titen®	#2 Phillips	3/16"	FL2355
1/4", 5"–6"	Flat	DeWalt Crete-Flex® SS4	T25 star	see product page	FL29068
1/4", 1 1/4"–4"	Hex washer	Simpson Strong-Tie Titen®	5/16" hex	3/16"	FL2355
1/4" x 5"	Hex washer	DeWalt Crete-Flex®	5/16" hex	7/32"	FL29068
1/4" x 6"	Hex washer	DeWalt UltraCon® SS4	5/16" hex	3/16"	Miami-Dade NOA

410 Stainless vs. 304 and 316

410 is a hardenable martensitic stainless. It can be heat treated to the hardness needed to cut threads into cured concrete at small diameters, which is why concrete screws are made from it rather than from 304 or 316. That hardness comes at the cost of corrosion resistance: 410 offers a good level of protection for exterior and high-moisture work, well above plated carbon steel, but it is not a marine-grade alloy. For direct salt spray, submerged or chloride-heavy service, use a 316 stainless Titen Turbo® concrete screw instead.

Key Features

• 410 stainless steel — good corrosion resistance for exterior and high-moisture use
• DeWalt lines carry a Stalgard® coating rated for 1,000 hours salt spray per ASTM B117
• Code listed under Florida Product Approval FL2355 (Simpson Titen®) or FL29068 and Miami-Dade NOA (DeWalt)
• Anchors into concrete, brick, grout-filled CMU and hollow block
• One-piece screw anchor — no shield, plug or expansion sleeve required
• Removable and reinstallable
• 3/16" and 1/4" diameters in lengths from 1 1/4" through 6"
• Flat head (#2 Phillips or T25 star) and hex washer head (5/16" wrench)
• Functionally equivalent to ITW Buildex® Tapcon® and Elco Crete-Flex® concrete screws

How to Install a 410 Stainless Concrete Screw

1. Look up the carbide bit for your specific part in the table above. Drill at least 1/2" deeper than the intended embedment to leave room for dust.
2. Blow the hole clean with compressed air. Dust left in the hole is the most common cause of a screw that will not seat or that spins out.
3. Drive the screw through the fixture with the drive listed for that part — #2 Phillips, T25 star, or a 5/16" hex socket — until the head seats. Do not overtighten; stripping the threads in the base material ruins the hold.

Frequently Asked Questions

What size drill bit do I need?

It depends on the line, not just the diameter. A 1/4" Simpson Titen® takes a 3/16" carbide bit, and so does the 1/4" x 6" DeWalt UltraCon® SS4 — but the 1/4" x 5" DeWalt Crete-Flex® takes 7/32", and the 3/16" Crete-Flex® takes 5/32". Check the table above or the individual product page. The bit is always smaller than the screw diameter because the screw cuts its own threads into the hole wall.

Are these the same as Tapcon® screws?

They are the same type of fastener. "Tapcon" is ITW Buildex's trademark for its concrete screw, and it has become shorthand for the whole category the way people say Sawzall for a reciprocating saw. The screws on this page are Simpson Strong-Tie Titen® and DeWalt Crete-Flex® and UltraCon® SS4 in 410 stainless — functionally equivalent to the stainless Tapcon® and to Elco Crete-Flex®. Same hole preparation and same head styles; confirm the bit size for the specific part.

Can I reuse a concrete screw?

The screw itself can be removed and reinstalled, but each reinstallation into the same hole reduces holding power because the cut threads in the concrete wear. For a full-strength connection, drill a fresh hole.

Is 410 stainless good enough for coastal work?

It depends on exposure. 410 stainless is well suited to exterior and high-moisture conditions and substantially outlasts plated carbon steel. For direct salt spray, splash zones or submerged applications, step up to a 316 stainless concrete screw — 410 is not a marine-grade alloy.

How deep should the screw go into the concrete?

Embedment depth drives holding capacity, so select a length that puts adequate thread into the base material after passing through the fixture. Subtract the fixture thickness from the screw length to find your working embedment, and always drill at least 1/2" deeper than that figure.