RE: Ambiguous Measurement Terminology

Date: Tue Feb 02 1999 - 12:41:50 EET

-----Original Message-----
From: Tromans, Graham
Sent: Tuesday, February 02, 1999 9:53 AM
To: 'rp-m@ltk.hut.fil'
Subject: RE: Ambiguous Measurement Terminology

Here in the UK we also have a measurement problem. Some of our
dimensions have to be within a Gnats c*ck. What I would like to know
is do we work closer than our colleagues in the USA? or does the Gnats
ass give tighter tolerances. Maybe this could relate to the HGA
measurement in some way. It all depends on whether the measurement is
length or diameter, and whether the GA measurement is whole or hole.
Is there any chance of a JPEG file of this part of the anatomy.


-----Original Message-----
From: Marshall
Sent: Tuesday, February 02, 1999 3:43 AM
To: KHVD07A; tomr
Cc: Marshall; rp-ml
Subject: Re: Ambiguous Measurement Terminology

From: Tom Richards <>

>I prefer the round number of 0.001-inches, or one "HGA", which is to
>one-Half of a Gnatt's Ass.

    But those of us who prefer metric would rather round it up to 0.1
mm, or
a TGA for 2 Gnatt's Arses.

Best regards,
Marshall Burns

***** Fabbing the Future(TM)
***** 10911 Weyburn Avenue, Suite 332, Los Angeles, U.S.A. 90024
***** Phone: +1 (310) 824-8700. Fax: +1 (310) 824-5185
***** E-mail: Web site:
***** Copyright (c) 1998, Ennex Corporation

>At 09:09 AM 2/1/99 -0500, you wrote:
>>-- [ From: Al Hastbacka * EMC.Ver #2.5.3 ] --
>>I have noticed that went RP people talk about measurements in mils,
>>there can be a great deal of confusion. The problem comes about,
>>because depending on the background of the person, this can mean
>>millimeters or thousandths of an inch. For example, 2 mils may be
>>interpreted as two millimeters or 0.002 inches.
>>In order to overcome this problem, I propose that we use a new
>> You have probably heard the statement that a "measurement was on
>>a gnats ass". In order to understand what this really means, I have
>>examined some photographs of gnats and measured what appears to be
>>ass. From these photographs, the average value of the gnats ass came
>>about to be 0.002 inches or 0.05 millimeters.
>>I am therefore proposing an unambiguous measurement amongst RP'ers to
>>GA units (GA is the abbreviation for gnats ass), where a GA is 0.002
>>inches or 0.05 millimeters.
>>What do you think?
>>Al Hastbacka

For more information about the rp-ml, see

For more information about the rp-ml, see

This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:50:52 EEST