Half Blind Dovetail — What It Is, Where the Strength Comes From, and the Numbers

A half-blind dovetail hides its interlocking pins and tails behind one unbroken face — the joint that lets a drawer front show a clean, uninterrupted surface while the drawer side behind it is doing all the same mechanical work a through dovetail does.

The same wedging action, stopped short on purpose

Strength comes from exactly the same mechanism as a through dovetail: the tails flare, so a force pulling the joint apart has to shear or crush wood rather than simply slide the pieces past each other, backed by real long-grain glue area on the flanks. What changes is that the pins are cut to a set depth rather than sawn all the way through — the drawer front's outer face stays solid, uncut wood, and the joint's interlock happens entirely within the front's thickness rather than passing through it.

How deep the blind cut goes

The pins are typically stopped around 3/8 of the stock's thickness — on 3/4" drawer-front stock, that's roughly 0.28", leaving a solid 7/16" or so of uncut wood on the show face. Go shallower and there isn't enough pin length left to develop real glue area or mechanical bite; go deeper and the show face gets thin enough to risk the router or chisel breaking through where it shouldn't, especially on drawer fronts thinner than 3/4".

Why this can't be sawn the way a through dovetail is

A through dovetail's waste between pins gets removed with a coping saw run straight through the board. A half-blind dovetail can't do that — the waste has to be chopped out with a chisel (or removed with a router and cleaned up by hand) because there's no way to run a saw through wood that doesn't go all the way through. That single difference is why half-blind dovetails are slower per joint than through dovetails even though the layout and angle math are identical: every bit of waste comes out by paring rather than sawing.

Cut sequence

1. Cut the tails first on the drawer side, exactly as for a through dovetail, staying just outside the layout lines on the waste side.
2. Mark the blind-depth line on the drawer front's inside face, set to roughly 3/8 of its thickness.
3. Transfer the tail shape onto the drawer front's end grain using the cut tail board as a template.
4. Remove the pin waste by chopping with a chisel down to the blind-depth line — never sawing through, since the front's face has to stay intact.
5. Pare the pin sockets to fit, test-assembling from the inside repeatedly rather than committing to a final pass before checking fit.
6. Dry-fit the full joint; because the front's face can't be seen into during test-fitting the way a through dovetail's end grain can, take extra care that the joint seats fully home before glue goes on.

The angle and proportion rules carry over unchanged

Slope ratio (1:6 for softwoods, roughly 9.5°; 1:8 for hardwoods, roughly 7.1°) and narrow-pin proportions follow the same reasoning laid out for the through dovetail — the mechanics of why a shallow angle risks fragile pin tips, and why pins stay narrow because they're mostly end-grain-to-long-grain glue, don't change just because the joint is hidden on one face.

The failure mode unique to a blind socket

A through dovetail's fit can be checked by eye from both faces while it's being pared — a half-blind socket can't, because the drawer front's solid face blocks any view of the bottom of the cut. The single most common way this joint goes wrong is a pin that looks correctly fitted at the visible edge but is actually bottoming out against uneven waste deep in the blind socket, holding the joint slightly proud rather than fully seated. Because that gap is invisible until the joint is driven home under clamp pressure, it's worth periodically checking socket depth with a small scrap gauge or a bent wire probe rather than trusting a visual check that can only ever see the first quarter-inch of a 0.28"-deep cut.

Scaling the blind depth down for lighter drawer stock

The 3/8-of-thickness rule assumes 3/4" drawer-front stock; it doesn't hold as a fixed dimension on lighter furniture built from 5/8" fronts. At 5/8" (0.625"), the same ratio gives a blind depth of roughly 0.23", leaving about 0.39" of solid face — noticeably less margin for error than the 7/16" a 3/4" front offers, which is why fine cabinetwork on thin fronts often backs off the ratio slightly (closer to a quarter of the stock's thickness rather than three-eighths) to keep a safer buffer against breakthrough, accepting a small amount of lost pin length in exchange.

Why the extra chisel time is worth it on a drawer front specifically

Half-blind dovetails are slower than through dovetails specifically because of the chopped, unsawn waste removal — expect meaningfully more chisel time per joint. That cost is accepted almost universally for drawer fronts specifically because no other joint at comparable strength lets the front show as one continuous, uninterrupted surface; a through dovetail or a box joint would both show end grain on the front face where a half-blind dovetail shows none.