Hillman Zinc-Plated Hex-Head Lag Screws Review (2026)
By Nate Sawyer, Editor · Updated July 2026
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4.6$12~$8–$15 per pack by size; e.g. 1/4 in. x 3-1/2 in. 100-pk ~$30, small packs ~$5Check Price on Amazon →
- Heavy into wood
- Into studs
- Ledgers brackets
Hillman's zinc-plated hex-head lag screws (1/4-3/8 in dia, up to 8 in) are the workhorse for pulling heavy things tight to wood studs and joists, with coarse threads that bite deep and a hex head you torque with a socket. But they almost always need a pilot hole or the wood splits, zinc isn't for outdoor lumber, and a wrench is required.
Pros
- Coarse threads bite deep into wood for serious holding power — the right pick for TV brackets, ledgers and heavy shelving into studs
- Hex head lets you apply high torque with a socket without cam-out
- Sold loose by exact diameter and length, so you buy only what the job needs
Cons
- Almost always needs a pre-drilled pilot hole — skip it and you'll split the wood or snap the screw
- Zinc plating isn't for outdoor/pressure-treated lumber (use hot-dip galvanized or stainless there)
- Requires a wrench or socket — no quick driving with a bare drill bit
Specifications
| Type | Hex-head lag screw (lag bolt) |
|---|---|
| Sizes | 1/4 in., 5/16 in., 3/8 in. dia; 1-1/2 in. to 8 in. long |
| Drive | External hex head (wrench/socket) |
| Material | Zinc-plated steel |
| Best for | Heavy fastening into wood studs & joists |
Frequently Asked Questions
- Do you have to pre-drill for a lag screw?
- Almost always. Without a pilot hole you either split the wood or snap the screw, and both failures happen at the worst moment — under load, in a finished surface.
- Why a hex head instead of a driver bit?
- It lets you apply high torque with a socket without cam-out, which is what a lag screw needs to seat fully. The cost is convenience: you need a wrench or socket, not just a drill.
- What size lag screw should you buy?
- They are sold loose by exact diameter and length — 1/4, 5/16 and 3/8 in diameters from 1-1/2 to 8 in — so buy for the actual joint rather than a pack. For outdoor or treated lumber, skip zinc and use hot-dip galvanized or stainless.