FIX AND FIT

If I had a Hammer

How hammers can come in handy­—for more than taking out your frustrations

there are several hammers used in ophthalmic optical work. Though many are left to collect dust, they can be very handy to keep around. Here’s a breakdown of type and use.

• RIVETING HAMMER. Probably the most common type of hammer used in optical is a riveting hammer. These usually have a flat face on one side and either a chisel or point on the other side.

The flat face may be used in conjunction with punches of various sorts. Some punches are designed to knock out a screw or rivet in older-style eyewear, and some that have a cupped end are used to mushroom the end of a screw or rivet to keep it from coming out.

The chisel-shaped or pointed end of this hammer is intended to peen the end of a rivet, which also mushrooms the end but is a different technique (perhaps even an art) that is rarely used enough to master.

• BRASS HAMMER. This type of hammer, which will often have a nylon face on one side, is sort of the “trusty persuader” you may have heard about. These may be used when an eyewire is a little out of shape, leaving a gap between the frame and lens. With the lens in the frame, tapping on the outer edge of the eyewire at the point of the gap will often settle an eyewire gap by reshaping the eyewire where it is out of shape.

One should use caution, however, and perhaps practice this on old pairs of glasses, as lenses can be chipped using this method. I have known older opticians who never worked with a plastic lens and used this method on frames with glass lenses for years.

• DE-BLOCKING HAMMER. Another type of optical hammer is called a de-blocking hammer. Its head is usually made of wood and has a shaft that is just a piece of springy wire attached to the handle. As the name implies, it is used to remove a lens from its block after it has been surfaced to its prescription. This takes a bit of good technique, but usually is not too hard to master. Just be careful you don’t hit your fingers.

And with all kinds of hammers, a little practice will go a long way.

— Alex Yoho

1. This steel hammer is used for peening a rivet, or striking the end of a punch; 2. A brass hammer with a nylon face provides heft to tap out a gap. It may also be used to strike a punch, but will deform in time