double ended calipers

[Brian Kent]

If I buy a 4" double ended (figure 8) caliper will I have a 4" reach, or a 2" reach?

Likewise is an 8" double ended caliper good for a 4" or 8" reach?

And is a Grizzly caliper set about the same as a Sorby caliper set of the same dimensions?

Thanks

[Ben Darrah]

Brian,
I have not been happy with the quality of the Grizzly measuring tools I have purchased in the past.

[Brian Kent]

Thank you Ben.

[Fred Belknap]

Brian I have a Sorby and I think it is called 7" and it will reach 6.75" into a bowl on both ends. One end is smaller which makes it easier to check near the rim of a hollow form.

[Brian Kent]

Thank you very much, Fred. That's what I need to know.

[Michael Mills]

I started with the double end and quickly went to the single end. For me it is much easier to look at the distance from the outside wing to the wood than to look at the change in the tips of the double end out in the air.
This style is what I am talking about...I have no knowledge of this seller... just the style caliper.
http://www.ebay.com/itm/L-S-Starrett-Co-10-Inch-Outside-Calipers-/200969142842?pt=LH_DefaultDomain_0&hash=item2ecab1c23a#ht_1418wt_885

The ones I have were too tight and I ground off the pin and replaced it with a small screw and wing nut to adjust the pressure.

[Thom Sturgill]

I've used a piece of 3/16" rod with both ends polished and then the rod bent into a circle. Set the ends to a 1" gap and then look at the clear space link Michael mentioned. one end is straight for about 1 1/2" while the other is curved. I also use this:
272272
I own the large ones. They are spring loaded so you can set the position to just rub, open them manually without changing the setting and pull them out and let them close and measure the opening. Very good for getting in deep, these are made by Veritas and carried by Lee Valley, Packard, and others.

[Harry Robinette]

I used double ended ones for years But changed to the Veritas about 6 or 8 months ago and love them. The spring is in the closed position not the open.

[robert baccus]

# 1 on the Veritas--great on vases as well as bowls.