Hole Dimension

[svrkjg]

Hello All,

 

I have a general question.

 

I have a PDF file I'm re-drawing into CAD form and I show a HOLE with the following dims

 

1.98 H7. The H7 is upward of the dim, not right next to it. I think it reads a + something and - 0.000

 

I read that the H7 is a tolerance of 0.0025mm. I've attached the drawing to get my meaning. I had the part made using this dim and the part (2mm Dowel Pin) slides easily in the hole. I measured th Pins and they are all 2mm.

 

Thanks in Advance.

 

KenJG

[iainlines]

Excuse me if I'm missing something but how does a 2mm dowel slide into a 1.98mm dia hole?

[SLW210]

Not really sure what is the question.

 

What does the hole actually measure? What did you measure the dowel pin with? What type of fit were you looking for?

 

Here is a chart, you really need the Machinery's Handbook if you do this often.

[svrkjg]

Hi, Thanks for the reply.

 

I had a hole drilled to a DIM of 1.98 +0.025 & -0.000. I have a Dowel Pin I purchased and it's 2mm Dia x 6mm LG. So the Pin slips in the hole. I'm not sure if I had used the right Dim H7 value. Still have not found what exactly H7 tolerance is.

 

Sorry for the confusion.

 

KenJG

*****

Excuse me if I'm missing something but how does a 2mm dowel slide into a 1.98mm dia hole?

[svrkjg]

Hello & Thanks for the reply.

 

Sorry for the confusion.

 

The hole after being drilled is about 2mm and the PIN I purchased is also 2mm exactly. I think I put the wrong deviation value. I read where H7 was = 0.025mm, is this wrong or right?

 

BR

KenJG

[ReMark]

I'm pretty sure you do know what a H7 tolerance is because the information was given to you at another AutoCAD help website earlier today.

[SLW210]

1.98mm + 0.025mm = 2.005mm

 

If you look at the chart I posted you will see for holes 1-2mm H7 = +0.010

 

1.98mm + 0.010mm = 1.99mm

[iainlines]

SLW210....thanks man, I probably should've taken the time to do the maths before replying to the post!