Another Broken Underwire! Why Do My Underwires Keep Breaking in My Bra?

August 5, 2008 by Tomima - 6 Comments


Strange but true: the underwire in your bra can occasionally break.  Usually right in the center and without warning.  Why does this happen?  I know of a couple reasons for this phenomenon, but as every good researcher knows, you also need to ask the experts. I  put the question to several designers and experts in the industry.  What came back was rather enlightening.  There are a number of causes for underwire breakage. Here is a list of  the 7 reasons bra underwires break.

  1. Washing your bra in the washing machine without a lingerie bag. – Now, we’ve all heard that we should stick our bras in a lingerie bag before throwing them into the washing machine.  But do you know why?  One reason is to protect the underwires. Without a lingerie bag, the wires can get caught in the agitator, stuck in one of the holes in the side of the drum, or get tangled up with another article of clothing.  All this this puts a stress on the underwire and causes it to break.
  2. Putting your bra in the dryer. – The heat from a dryer can affect the chemical make-up of the steel in the underwire and cause it to become more brittle.  Additionally, if put your bra in the dryer without a lingerie bag, the wires can get caught in the dryer’s drum hole and be twisted into a shape that reduces its strength.  And, similar to what happens in the washer, your bra can also get caught on other clothes thus causing stress to the underwire and compromising its strength.
  3. The metal used in less expensive bras may not be tempered (or heated) to the appropriate temperature and therefore is brittle and will break more easily. – My friend Ellen Jacobson – designer/owner of Elia bras – explained this to me.  Tempering is critical when making steel for underwires.  She went on to say that most underwire manufacturers have excellent product.  This usually becomes an issue when a manufacturer is trying to cut corners and buys their underwires from an unreliable source.
  4. Round underwires break more easily than flat underwires. – Wire as we think of it is round.  If you hit it with a hammer, the shape becomes flatter.  Most underwires today are flat.  However, again, in less expensive bras, manufacturers may purchase round wire because it is cheaper since less production goes into molding round underwires.  You can quickly tell if an underwire is round or flat by simply feeling the underwire between your fingers.
  5. Underwires without a plastic coating are more susceptible to breaking. – My good friend John Gilpin at Wacoal – America turned me on to this reason. As John explained, the better bras use underwires that have a plastic coating over the wires.  This coating smooths the edges and allows the underwire to slide more easily in its channel.  This movement reduces the chance of pressure or torque on the wire that could cause it to break.
  6. Your bra band is too tight. – Underwires are designed to splay when the bra is worn.  This helps the bra to actually grab your breasts and give them support.  If your bra band is too tight, you are pulling the underwires apart farther than they are designed to be pulled.  This stress will eventually cause the wires to break.
  7. Your cup is too small. – Underwires are designed with a certain volume of breast tissue in mind.  If you exceed that designed amount of mass, the underwire is again stressed and forced to splay beyond what it was designed to do.  This kind of pressure on the underwire over time will eventually cause the underwire to break in the center where the greatest pressure is being exerted.  The Le Mystere design team told me they’ve seen underwires under this kind of stress actually shred (rather than break cleanly) and create thin sharp shards of metal… ouch!

bra underwiresSo what’s a girl to do?  Well, there are several precautions you can take to prevent underwires from breaking.  First, be careful how you launder your bras.  Ideally, they should be hand washed and hung to dry.  If you can’t do this, at least fasten the hooks and place your bras in a lingerie bag in the washing machine.  Never put your bras in a dryer.  It simply ruins them.

Next, make sure you are in the proper size bra.  There are more wire breaks because the cup size is too small than because the band size is too small.  A bigger cup size will capture more breast tissue and have a larger underwire to catch the sides of your breast more comfortably.  The wire will then anchor more smoothly in the breast crease without stretching to its eventual breaking point.  And, you get the added benefit of eliminating that pesky pinching feeling because your underwire won’t be as narrow and resting on top of your breast tissue.

Finally, get a good feel on your underwires.  Are they flat?  Also, If you can feel a sharp edge to them, they probably aren’t coated and will eventually saw through your bra and/or break.

Treat your bras with proper care, make sure you’re wearing the correct bra size, and buy quality bras.  This will reduce if not eliminate the chances of your underwires breaking.

The fitting guide on HerRoom has solutions to many more common bra fitting problems.



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