HCA: Hermit Crab Association

I was looking at shells to order from Richard's, particularly fluctuosus, and it says the opening is 59/64th which I don't think is accurate. I'm concerned that may be too small.

i found some awesome shells at Naples. They have the shell size AND the opening size, so it helps you pick a little easier. They have great prices too! I've never ordered from Richards though....

I love Richards! You would need to tell them that the shells are for hermit crabs so that they check them for holes, etc. Do you have a caliper? That is how they measure the shell opening. You can pick up a relatively nice one on amazon for around $8. I personally prefer the digital ones.

I have a caliper but I use measuring tape to measure my shell openings.

crabby33 wrote:I have a caliper but I use measuring tape to measure my shell openings.

A caliper is more accurate at measuring the inside of a shell than measuring tape would be.

I was actually hoping to find guidelines for Richard's measurements. I've seen opening sizes for 32/64th and 14/32nd and various other sizes. I'm assuming that's in millimeters? Why are some listed in mm and others in inches?

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My guess is they’re measuring the length of the shell, not the opening. I prefer to buy from places that measure the opening hole. Like Mygann’s or Naples.

They have separate numbers for shell length and shell opening, so it's definitely shell opening. I think those measurements are fractions of an inch, when I think about it some more. It was kind of confusing for a while, I'll be honest haha. But I think that's what I'll go with. Thanks!

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It is fractions of an inch, units so small that really only carpenters and other professions that need exactness use. It's kind of silly when it comes to hermit crab shells. 1/8 is plenty!

wodesorel wrote:It is fractions of an inch, units so small that really only carpenters and other professions that need exactness use. It's kind of silly when it comes to hermit crab shells. 1/8 is plenty!

Thanks for the confirmation! I had been about to email them about it but was like... Let's ask someone first ::)

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59/64 is between a 7/8" and 1", only 1/32 under 15/16
32/64 is a 1/2"
14/32 is 7/16"

We build wooden roller coasters and for the structure we generally will only go to between 1/8" and 1/16" for cutting the lumber. Most tape measures only go down to measure to 1/16". A 32nd is half of a 16th. A dime may be around 1/16" thick. Wodesorel is right. Shells for crabs only need to be broken down 1/8". I can't see a crab getting that particular with choosing a shell.

Tnguo wrote:I was actually hoping to find guidelines for Richard's measurements. I've seen opening sizes for 32/64th and 14/32nd and various other sizes. I'm assuming that's in millimeters? Why are some listed in mm and others in inches?

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Millimeters do not measure in fractions - its small enough anyway, and anything smaller will require high tech equipment/microscope.... If you want to measure a half (or whatever unit) of the metric system, its commonly accepted to round off or use decimal.

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