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What are some valid considerations to help decide whether drawbore holes should be blind? (or go through the back)

I'm building a roubo-style bench with thick douglas fir legs (4"x6") and stretchers (2"x6"). The stretchers are joined to the leg with mortise and tenon. In the instructions, the tenons are preferably drawbored tight against the legs.

However, it is not specified whether the drawbore peg should go through the stretcher and leg completely (i.e. so the peg pokes out at the back of the leg), or whether to make the drawbore hole stop shy of the backside of the leg.

I have limited drawboring experience, but I have some concerns (which may or may not be considered valid by an experienced woodworker):

  • Longer pegs break more easily.
  • In other projects with softwood, I've also had chip breakage on the exit side around the peg hole.
  • I was planning on using 3/8" dry dowel and a 23/64" hole (i.e. hole is 1/64" smaller), and make the holes 1" away from the edge of the joint. Maybe dowel diameter doesn't change much of anything, others seem to settle on approx 1/2" peg for that bench.

drawbore location

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  • Is part of the reason for the drawbore to have the ability to disassemble? If so, a through hole is way easier.
    – Aloysius Defenestrate
    Commented Jan 5, 2022 at 1:00
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    Good luck getting a 3/8” dowel into a 15/64” hole!
    – Caleb
    Commented Jan 5, 2022 at 3:51
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    @Caleb ah! i meant 23/64th, i.e. 1/64th smaller. will edit. excuse the arithmetic. the one time i did that, i “shrunk” the dowels beforehand in the oven (or microwave) to shrink them before hammering them in. the hole, being a smidge smaller compensates for some of the irregularities in the drill hole and on the circumference of the dowel (esp if you’ve punched it through a dowel plate).
    – ww_init_js
    Commented Jan 5, 2022 at 4:57
  • @AloysiusDefenestrate I wasn’t planning on ever disassembling the base, but i believe you may be on to something with that comment. Is ease of disassembly the only thing worth considering? I’ve never taken a drawbore apart… is that simply done by knocking the old dowel halfway out with a pin? (assuming it’s not glued in place)
    – ww_init_js
    Commented Jan 5, 2022 at 5:14
  • Hey, long time no see. Congrats on what may be your forever-workbench build! There are a few key drawbore points hidden in the body text and in the Comments, I think they're mostly covered in the links provided by @VolframK but do ask a separate Question to cover them if you'd like.
    – Graphus
    Commented Jan 5, 2022 at 14:20

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It does not matter. Through hole or stopped hole, hold of pin is the same.

Drawboring Resurrected
Drawboring Demystified

Reason not to bore through is if you do not want to see pins on both sides of leg, does not seem important on workbench. In theory drawbore pins through leg can be knocked out later if needed, but best of luck if you try!

In other projects with softwood, I've also had chip breakage on the exit side around the peg hole.

Does not matter. Workbench, not furniture!

Reminder: drawboring is option, not requirement. Many workbenches do not have drawbores, all joints still tight after 70+ years. How old are you? :)

Good reason to use them today is if clamps long enough are not available.

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