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2023-11: Warosu is now out of extended maintenance.

/diy/ - Do It Yourself

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294153 No.294153 [Reply] [Original]

going to do this just wondering how hard it will be. never done a tap before. this is for hub caps for my steel wheels on my car. they go on with bolts and i gotta drill holes in the wheels. using the tap isnt it like a half a turn then back it out? also will it matter what kind of drill? im planning on using whatever my dad has at his house. thanks.

>> No.294182

to make a solid thread you need the exact right bit for the tap. almost always it's not a standard size. like your photo which asks for a 6.8mm, which is def. not standard. you get the bit from a well-equipped hardware store. there's tables on the interbutts which tell you what size drill for each tap.

you can drill using a standard size that's smaller. then when you enlarge with the proper bit, you can concentrate on making the hole perpendicular.

for tapping, you just screw it in, again close to 90-degrees, and when you feel it's taking too much pressure, back off half a turn or more, and go again. you can use a small brush to clean out the metal filings.

practice tapping beforehand on something soft, like acrylic. taps are strong but brittle. if you push too hard they will snap like an icicle.

>> No.294198

>>294182
> taps are strong but brittle
Man, oh man, this. Breaking a tap in a workpiece will take so much time to get out, it isn't funny.

To add:
MAKE SURE that the tap is well aligned with the hole. Start slow as it tends to grab randomly at the very beginning (before any threads are cut). Use both hands on the wrench, and when it first starts to cut all of the way around, double check to make sure the tap is running straight through the hole. If it isn't back it out and try again.

The only PITA part is getting it started straight, and that's more of a patience thing. After that, like it has been said, cut about 1/4 turn at a time, turning the tap backwards to break the chip. Oil helps, and I've found that when tapping deep holes, every now and again you need to turn back 1 or 2 full turns instead of 1/2.

>> No.294206

>using the tap isnt it like a half a turn then back it out?
yea, if you use regular hand taps.
if you don't already have a tap for this, then order a spiral-point tap online. you don't need to reverse them at all, you just screw it all the way in. Look for an H2 or H3-fit. Enco is one place to buy them, if you are in the USA.

(the spiral-point will probably cut way easier than a cheap hand tap will anyway.... department-store taps are *almost* always absolute shit)

as for drilling, this will work a LOT better in a drill press than with a hand drill. when you use a hand (-held) drill to drill holes in thick metals, two things happen: the hole is never perpendicular, and you tend to snag the bit as it exits the far side, often breaking the drill bit. Using a drill press will prevent both these things.

>> No.294207

Use some cutting oil, go a bit of a turn, then back off and repeat.

Or in fact don't do this at all, because this shit looks like the height of bolt-on car gayness.

>> No.294211

>>294182
>to make a solid thread you need the exact right bit for the tap. almost always it's not a standard size. like your photo which asks for a 6.8mm,
ummmm,,,,,, yea it is.
6.8mm is the drill (hole) size for using a (metric) 8 x 1.25 tap in

http://www.newmantools.com/tapdrill.htm

,,,,,, you can also use a drill press as a tap guide, if you can clamp the work (the wheel) to the table to hold it still somehow. That way you know the tap will start perpendicular.

>> No.294225

>>294206
Spiral point is going to be much harder to start than a taper if he's doing it by hand only.

>department-store taps are *almost* always absolute shit
Ah yes, I have a set of some shit ones. HSS is so much better than the common carbon steel ones, something I wish I'd known when I got them. I've replaced a few of the ones I use most frequently due to small parts of the cutting teeth breaking off over time and leaving a ragged thread.

Do you have a hand tapper? Every time I have to tap a hole (which isn't that often), I ask myself why I haven't built one yet.

>> No.294228

>>294207
bolt on car gayness? they're the police edition caps for chevy impalas, not a fucking honda civic. anyways you guys have me nervous now. i have the tools. do you think i should ask a shop? how much do you think a shop would charge for this?

>> No.294230

>>294225
the only place i could find a metric set was harbor freight. set came with a hand tool i believe not sure bought it a while ago. i think the brand is pittsbrugh or something like that would have to check.

>> No.294232

>>294228
>anyways you guys have me nervous now
What, are you serious? I couldn't tell you about the car part (it does look dubious), but tapping a hole is not hard at all.

Watch this:
>http://www.youtube.com/watch?v=veO270DcKXE
He does everything. It is as hard as it looks in the video.

>how much do you think a shop would charge for this?
A shitton for wasting their time.

>> No.294237

>>294232
video is very helpful thanks. it will be a pita because i have to take the wheels off one at a time and do 3 hole drills/taps per wheel. i just don't want to fuck it up. what about just drilling holes and using a washer/nut on the other side? do you think somehow with the wheel vibration the nut could come off in time with no threads on the bolt?

>> No.294247

>>294237
Just tap it you fucking homo. This is like, woman level DIY. Drill a hole, put a fucking tap in, turn it slowly backing off every once in awhile. It's not exactly painting the Mona Lisa.

>> No.294387

Well, looking at the picture, how much is there space behind there? I'm guessing that you can't fit a nut behind there, so you need to do the tapping.

Also, what about the wheel balance? You sure it won't start shaking the tires for not being balanced? feels freaking horrible on higher speeds. (well, the bolts do come quite close to the center, but still...)

regardless the way how you make it, and you don't ever plan on removing them, then i suggest that after you have screwed the bolts on place, use a spike to hit at the backend of the bolt so it widens a bit... or use loctight.

>> No.294390

OP, i'd be very careful doing this to a set of rims.
Tapping its self is pretty easy, as long as you have the correct cutting compound and sharp tap.|
But drilling into a load bearing feature of a car is a big no no IMO. Give the wheels enough sideways stress, they could crack at the drill holes

>> No.294391

Use lubricant (motor oil, WD-40, diesel, whatever).
If you can't get a 6.8mm drill, use the closest imperial (why the fuck do you yanks still use imperial anyway, it shits me to tears having to convert fractional inches to metric), or even a 7mm bit will do, you will only loose 0.1mm from either side of your thread.
Then just go in slow a few turns at a time.
Use the starter tap and go all the way until it's easy to turn. Don't bother with the other taps, they're for a blind hole so you can get the thread all the way down to the bottom of the hole.
TL;DR, Treat it like sex with a virgin.
Lubricate well, take it easy, and back out and go back in every so often.