Hole Wizard Countersunk Hole *Not* ANSI

[brengine]

I have been trying to find the ANSI standards for metric countersunk hole dimensions. The only place I've found on the Internet is:

http://www.a-sp.org/Standards/chapters/assembly/F1-23.pdf

The values there correspond to the results we've been seeing here...if the holes are machined according to the default ANSI values in the Hole Wizard, then the Flat Head screws will not mount flush.

Can anyone out there verify this for me, or correct me if I'm wrong? For now I'm going to go into the Hole Wizard database and modify the hole sizes there.

Thanks,
Ken

 

[smcadman]

I would double check another source before modifying the database. I have read that SW uses the Machinery Handbook for data. I do not use metric screws, but I made a part with a few hole wizard holes in a row, and then I made an assembly an inserted a few metric screws flush with the top. I then made a cut-section through the hole centers and the screws, and everything looked correct. For example, an M8 screw had .0014 gap between the head and the countersink hole.

Then again, hopefully no-one else modified your database.

Flores
SW06 SP4.1

 

[CorBlimeyLimey]

Ken ... where are you getting your FHS from? What standard are they modelled to?


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[looslib]

I looked at a M3 in ASME B18.3.5M-1986 and it shows the dimensions for the head height as 1.86 and the countersunk depth as 1.61.

It looks like you have to overdrill the countersink depth to get a flush fit.

I just created a countersunk hole in Wildfire2 and its depth is 2.11, with a top dia of 6.72, whcih matches the specs.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
Sr IS Technologist
L-3 Communications

 

[brengine]

I did not measure the fasteners. I will do that next.

I could not find ANSI standards for metric FHCS holes in Machinery's Handbook.

Comparing the SW Hole Wizard countersunk large diameter, to the hole values at the website I mentioned above and the fastener dimensions in Unbrako...will result in every size above M4 not being a flush mount.

Our internal cross-reference table in Excel used by our AutoCAD system has values for FHCS holes and those values went along with what I found at that website, not with what is in SW Hole Wizard.

I'm not sure if this is a Hole Size or a Fastener Size issue (not being in spec. with ANSI), but something is definitely not right.

Ken