15MM Tap......Drill Size

[boslab]

Light bulbs use a completely different thread all together.

I did think the ES screw was metric, like E12 is 12mm, E26 was 26 MM etc, have I got it wrong?
Mark

[MattiJ]

Light bulbs use a completely different thread all together.

Yeah, how on earth americanos use E27 bulb socket?
Shouldnt it be something like 1" 7/128" edison socket?

[Puckdropper]

Dont worry.Eventually you guys will see the light

Light bulbs use a completely different thread all together.

[plunger]

yup, its one redeeming feature

Dont worry.Eventually you guys will see the light

[danlb]

I have 15MM 1.0 tap for a special job. I can't find a chart anywhere that gives the drill size. Every chart I've found goes from 14MM to 16MM. Why do they all skip 15MM ??

JL.................

The ISO standard apparently includes the concept of "preferred" sizes and pitches. Sometimes the pitch will be such that it makes for a weaker fastener (or so I was told) and so those are normally skipped. Those sizes are still in the ISO standard, they are just part of a "less desirable" class.

Some of the metric minded folks are convinced that you should never, ever use the size/pitch combinations that are not in the preferred group. Others point out that you can make a valid metric thread using any diameter and any pitch as long as it is measured in mm and meets the standard for the thread form.

Dan

[Highpower]

Why do they all skip 15MM ??

JL.................

Here's one.

[thaiguzzi]

15mm is a common spindle size for metric motorcycles. Wheel spindles, swing arm spindles etc. Have seen 1.25 as well as 1.00.

[JoeLee]

Doesn't the fit % matter?

Yes it does. I would like 75% thread engagement. The charts I have all show 65% and 75%.

larry_g posted this:

,,,,,,,,,,,,, inch ....metric %
M15x1.00 0.5492 13.950 81
M15x1.00 0.5512 14.000 77
M15x1.00 0.5531 14.050 73
M15x1.00 0.5551 14.100 69
M15x1.00 0.5571 14.150 65
M15x1.00 0.5591 14.200 62

I'm guessing the last numbers are the % of thread engagement with the appropriate drill size listed after the tap size.

JL...................

[JoeLee]

The reason it is NOT on most thread charts, is because it's not a normal sized thread, somehow you have got your hands onto an oddball sized tap.

I have an odd ball job to do.

JL................

[elf]

It is easy. 15-1=14 mm. This is your hole size for tapping. It goes the same way for all metric threads. OD-pitch=hole size.

Mike

Doesn't the fit % matter?

[j.bain87]

The reason it is NOT on most thread charts, is because it's not a normal sized thread, somehow you have got your hands onto an oddball sized tap.

[Doozer]

It is easy. 15-1=14 mm. This is your hole size for tapping. It goes the same way for all metric threads. OD-pitch=hole size.

Mike

It works for inch threads too.

--Doozer

[larry_g]

http://www.guhring.com/documents/Tec...utTapDrill.pdf

I use the above chart. It gives the estimated thread depth for various tap drills.

,,,,,,,,,,,,, inch ....metric %
M15x1.00 0.5492 13.950 81
M15x1.00 0.5512 14.000 77
M15x1.00 0.5531 14.050 73
M15x1.00 0.5551 14.100 69
M15x1.00 0.5571 14.150 65
M15x1.00 0.5591 14.200 62

lg
no neat sig line

[Arcane]

It works the same for all threads with a 60^o included angle.

[Mcgyver]

It goes the same way for all metric threads. OD-pitch=hole size.

yup, its one redeeming feature