Match screw gauge, length, and thread type to your joinery application and species.
| Gauge | Shank dia. | Typical lengths | Drive | Best for |
|---|---|---|---|---|
| #4 | 0.112" | 3/4″–1″ | Phillips / Square | Small boxes, hinges, light hardware |
| #6 | 0.138" | 1″–1-5/8″ | Phillips / Square | Cabinet hardware, thin face frames, small trim |
| #8 | 0.164" | 1-1/4″–2-1/2″ | Phillips / Square / Star | General cabinet construction, face frames, shelf pins, most furniture joinery |
| #10 | 0.190" | 2″–3″ | Phillips / Square / Star | Heavier joinery, stair treads, structural connections |
| #12 | 0.216" | 2-1/2″–3-1/2″ | Phillips / Star | Heavy-duty framing connections, ledgers, large structural members |
| #14 | 0.242" | 3″–4″ | Star (Torx) | Structural and heavy timber connections |
#8 is the workhorse of the cabinet shop — covers most face-frame, box, and hardware jobs. Always drill a pilot hole in hardwood; in softwood or end grain for any gauge.
| Type | Sizes | Thread | Notes |
|---|---|---|---|
| Pocket-hole screw | 1″–2-1/2″ | Coarse (soft) / Fine (hard) | Pan or washer head; designed for pocket holes at 15°. See Pocket Hole Calculator for sizing. |
| Lag screw / lag bolt | 3/8″–3/4″ dia, 1″–12″ length | Coarse / partial thread | Driven with a wrench or socket, not a screwdriver. Used for timber-to-timber and hardware connections. |
| Brad nail (18 ga.) | 3/4″–2″ | N/A | Very fine shank — minimal splitting. Good for light trim, small mouldings. Little holding power without glue. |
| Finish nail (16 ga.) | 1-1/4″–3-1/2″ | N/A | Standard trim nail — sets below surface and fills. Good for casing, base moulding, stair treads. |
| Confirm (barrel) bolt | 5/16″ dia, 25–50 mm | Euro thread | Used with a cam connector for flat-pack / knock-down furniture (32 mm system). |
| Dowel screw | #8–#12 | Coarse both ends | Both ends are threaded (no head). Used to join two wooden pieces end-to-end or to thread into end grain. |
| Connector bolt | 6–8 mm dia | Metric | Goes through one piece and threads into a barrel nut in the adjacent piece. Common in flat-pack furniture. |
Screw should penetrate the receiving piece by at least ⅔ of the screw length. For a ¾″ face frame into a ¾″ box side, a 1-5/8″ screw leaves about 7/8″ in the box side.
Use the screw supplied with the hinge; it is sized for the hinge leaf thickness. If substituting, never go shorter. For soft wood, one size up adds grip.
Bolt should protrude 3–4 threads beyond the nut or threaded insert. If through-bolting a drawer front, measure actual door + front thickness and add ¼″.
For structural connections, lag should penetrate the main member by at least 8× the shank diameter. Pre-drill with a full-shank clearance hole in the first piece.