I bought a dial bore gauge from Eastwood but I dont know how much each mark represents because Im stupid and Ive never used one before.

I think they said it graduates in .0005" (5 ten thousandths) increments or at least .0005 is on the guage face. But then the gauge also says the range of 0 - .25". Im assuming the "25" on the face is .25". And theres 50 markes on each side.

.25 divided by 50 is .005" (not .0005" like I thought)



How much is each mark worth? A 0 makes alot of difference!


Modified by Muckman at 7:46 PM 8/18/2005

 

Each mark is worth .0005" either plus or minus from the zero mark. It will take 10 marks to get to the number 5 which is .005". This works in the plus or minus direction. It tells you if you are over or under your zero mark.
.250" is the total travel of the guage.

 

If the number 5 is .005" then number 25 would be .025". The math is what I keep getting stuck on.

 

THe needle will spin around the entire gauge face 5 times to hit .25" of travel. Each trip around the gauge face is .0500" of travel. Multiply that by 5 to get .25".

Don't let the .25" number bother you. It's not a number you need to worry about. Just know how to read what's immediately on the gauge face.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">If the number 5 is .005" then number 25 would be .025". The math is what I keep getting stuck on.</TD></TR></TABLE>
0.0 is zero
0.1 is one tenth or one hundredth of an inch
0.01 is 10 thousandths of an inch
0.001 is one thousandths of an inch
0.0001 is one ten thousandths of an inch
So if .0001 is one ten thousandths and .001 is one thousandth then .0005 is 1/2 a thousandth of an inch.
Every small line is one 1/2 a thousandth and every large line is one thousandth.

 

ahhh now it all makes sense. Thanks guys!