The Metalworking Dilemma: Stretch or Shrink?

metal workingGrowth continues to push forward the metalworking industry, and that is good news for every machinist. Figures from IBIS World show that the annual growth of the sector has been at 5.5% since 2009, thus cementing its spot as a $29-billion industry. As a result, more and more hobbyists and enthusiasts venture into metalworking and turn this craft into a business.

But of course, the field has its own challenges. Newbies, for one, often have a hard time deciding on what they would do on a piece of metal – which is better: shrink or stretch? Lyndex-Nikken says it depends on what you are doing and what tools you have available. Here’s a more detailed explanation of two methods:


When you “shrink” metal, you press a section of the piece onto itself. This means you are not reducing the metal content of the piece; you are simply reshaping it together so that one section would appear thicker. This is actually the safer way to mold metal into a certain shape, as you do not meddle with the tensile strength of the piece no matter what tools you use for the craft. If anything, the folding and pressing action reinforces its strength and makes it more durable. Shrinking is ideal for flat panels that need to be thicker in certain areas.


Stretching is the polar opposite of shrinking, but it does not mean that it is always bad for your piece. Instead of adding extra layers or folds into the metal piece, what happens is that you reduce its thickness and spread its dimensions. When you need to work with curved and thick panels, stretching is your main options. Do note that unlike shrinking, stretching runs the risk of damaging the piece if you overwork it, so be sure to factor in the material’s tensile strength before you stretch.

For the best results, observe this rule: shrink flat panels and stretch curved ones. Now, if you think both methods may apply, always go for shrinking first, so that it will be easier to stretch later on.