Fabrication of a box clasp

Hello All, I am having 3 problems fabricating a box clasp for a
bracelet that I have dreamed up, and would appreciate any help you
all have to offer.

Problem #1: I am not sure if I am going about the construction in
the right order/ manner

Problem #2: I am unable to maintain “springy-ness” (hardened) to the
tongue, as it is soldered (and annealed) 3 times during


  • solder top of clasp to sides of clasp

  • solder tongue to bottom of clasp (#1)

  • bend tongue to achieve proper alighment with other half of clasp

  • solder oval prong head to top of tongue, again achieving proper
    alignment, with the top pattern of the clasp. (#2)

  • solder top half of clasp to bottom of clasp. (#3)

  • (please feel free to correct me at any time!!!)

I am currently working in sterling silver, but I want to finally
construct in a way that this can ultimately be rubber-molded, and
perhaps cast in 18k.

The clasp: A north/ south rectangle, two mirror-image halves.
(height=24 mm, width= 20 mm total, 10 mm each halve) (The large clasp
size was determined by the need to accommodate 6 strands of small

The bead and bright, and pierced patterns on top of the clasp are
coordinated with the front oval piece for the bracelet. (the tongue
must remain “hidden from view” when the clasp is viewed from above)

The tongue (6 mm wide) sticks out of one half, and goes "click"
into the other half.

The tongue will have a prong head for a 4x6 oval soldered (?) on
top, which will stick up and be integrated into the top pattern on
the clasp. It will “straddle” the gap between the 2 halves of the

This prong head will be the “button” that will be pushed down to
disengage the clasp.

I find it difficult to hammer and “work- harden” the tongue after it
has been bent, but I feel I need to bend to get alignment. (Am I
constructing in the right order?)

I read somewhere (but now cannot remember where) that one can also
"heat- harden" metal.

I would like to know how to do this as well, for future reference,
as I do not currently own any kind of kiln.

Problem #3: I don’t know if i can mold the tongue half of the clasp
with the tongue bent, or if it needs to be straight (for wax
removal)…but I feel that I have to bend the tongue eventually,
in order to check/ get a precise “fit” or alignment of the oval,
with the center of the pattern on the top of the clasp. The oval
"straddles" the gap between the two halves of the clasp.

(Would you believe me if I told you I have been using the “trial and
error method” on this project since June?)

(In a moment of frustration, I did look for ready- made clasps, but
could not find one that was the right size for the number of strands
that I was using, or one that would coordinate well with the front
oval piece.)

Thank You in advance!
Julie Balonick

Julie, Take a look at the “Box Clasp” construction project in Alan
Revere’s Professional Goldsmithing: A Contemporary Guide to
Traditional Jewelry Techniques. It provides the basic in box
clasp-making. After working through it step-by-step you get a
great, I mean great understanding of how it is made. Then
reconfigure it for your needs.

Try using 80/20 (reticulation) silver sheet for the tongue. It will
maintain better spring than sterling. When you solder the end plate
(sterling) onto the tongue, use a heat retardant on and around the
corners so it doesn’t “reticulate”. It’s a bummer to have to re-do!

I would think that you would have to hand fabricate the tongue,
because of need of spring in the metal. All other parts of the
clasp could be cast.

The “button”, or some call it the trigger, gets a lot of use, so
needs to be workable, comfortable and DURABLE. The prong setting
would have to be extremely heavy duty to fit the bill. Hard solder
a must here.

Good luck,
Kay Taylor

After making your box clasp, adjust it properly and take a small
dollop of silicone sealer and rub inside the o spring when it hardens
it will act as a rubber spring. Some trimming of the hardened
silicone may be necessary after it dries

Hi Julie, In my experience, the tongue is best fabricated, every
time, from one strip of metal long enough to fold and mill to
harden. Longer than you need for top and bottom length is

In the use of silver, there are complications. The heat required for
assembly will often anneal the clasp. The use of a heat-sink, such
as locking tweezers on the folded end will lessen the annealing
effect, but it will soften. A good method of contruction which will
allow you to harden it without hammering, (which can be inneffective
with silver if it has been constructed of thin material) is to
assemble it prior to folding, which requires precise design. Mark
where you wish the button to be, solder it on, solder the butt-end
of the tongue to the wall of the catch, then lightly score and bend
the assembled tongue to the correct position to fit into the box,
and trim to fit. Some hammering may be required to finish the fold,
but the hardening will be successful.

Casting these pieces will create difficulty for you. In my repair
experience, most often the tongues that fail are cast, or improperly
hardened. Failure of clasps causing loss of the items are a big
negative for your career. It is not easy to make a good clasp, but
it is a measure of your ability as a craftperson, in the same way
that carpenters are judged by their skill at hanging a door. Work
out a design, practice, make improvements, keep records of your
measurements and revisions, and then you can repeated successes with
your clasps, and minimize your frustration.

I hope my explanation was clear enough. Wish I could draw on this


After making your box clasp, adjust it properly and take a small
dollop of silicone sealer and rub inside the o spring when it
hardens it will act as a rubber spring. 

What a great idea! Not only does it act as a rubber spring, but it
reduces the possibility of the metal cracking after repeated use. Dee

Julie-I didn’t respond right away on this topic because there are so
many with much more knowledge and experience than I - but I haven’t
seen anyone talk about the difference in fabricating a box clasp in
sterling vs. gold. I have made a few and started by following the
instructions in Alan Revere’s Goldsmithing book - but those
instructions are for gold. In sterling, most everything is the same
except you must make the tongue longer - about 1/2 again as long -
in order to get the spring you need. (this usually also means that
the overall shape of the clasp needs to be changed to accommodate the
longer tongue) Sherry Reed

Julie: I make a lot of box clasps. I always use nickel silver for the
tongue. It doesn’t lose it’s spring like silver and is easy to work
harden if it doesn’t “snap” enough.

Hope this is helpful.