Cutterhead lock bar screws on a mid 80s Delta DJ-20...

[Steven Valentine]

Maybe this is a stupid question, but I don't know, so I would rather ask...I have an older DJ-20 8" jointer that I picked up a few months ago. I'm just getting the chance to use it more, and dulled the knives on it (after several hundred feet of hard maple). Anyway, while replacing the knives, I noticed how tough the M6 1.0 screws were to get out. The heads are worn out and rounded over, so they need replaced. My question is: what grade do these screws need to be? I found 8.8 which I believe is a grade 5 at Ace Hardware, but is this good enough (not to cause me to lose any digits). The guy at Ace told me he thought they made a 10.8, but is this neccessary, or will the screws I found at Ace be okay. I cannot seem to find this info anywhere, and you guys are always so much help, I figured I just ask. Thanks in advance...

[Pete Bradley]

This topic has been extensively discussed on the forum at www.owwm.com. The upshot is the Delta screws are pricy, but what you need.

[Steven Valentine]

The only info I've seen so far on this comes from Delta manuals, and replacement part sites, like eReplacement parts and toolpartsdirect which call it "special screw". Way to be vague about it Delta. The machine is not too old, probably mid 80s. I know the lockbar screw is M6 1.0, I simply want to know how hardened it is. Any other info is appreciated.

[Chip Lindley]

Steven, the 8.8s should be just fine. Problem is, most have raised numbers on the cap which need to be honed off. Gib screws must have a smooth head.

The purpose of hardened screws is as much to keep the wrench from rounding over the hex head as for thread strength. Would be hard to twist off a gib screw, as the head is fully against the cutterhead body; threads pushing the gib against the knife. No free play to twist one off! But hardened screws can't hurt!

[Steven Valentine]

Gave up on taking the chance. Went ahead and bought the screws from Delta (98 cents a screw, plus 10.50 shipping for the 12)...what a racket? Anyways, thanks for the help.