Drilling for Better Results

By Bob Woyton
Since the introduction of drilled rimless compression mounts there have been many advancements in rimless eyewear fabrication and adjusting techniques including the removal, replacement and adjustment processes.

Rimless tools needed: Compression removal pliers– safely separates the compression mount Compression pliers – compresses the assembly together Bushing Cutting tool – cuts nylon bushings Bracing Pliers – braces frame for any adjustment without lens damage Beveling tool – Chamfers lens hole to eliminate lens stress and cracking Rimless Punch – removes all compression debris from lens


There are instances in which assembled mounts need to be separated and replaced. It could be to change the Rx, replace a faulty mount or change a broken frame component. To safely remove the compression sleeves without risk of damaging the lenses or frame, compression removal pliers are recommended.

Trick of the Trade

Before attempting to remove the hardware, cut the bushing at the point that bridges the two sleeves together. This makes removal much easier. Place the compression removal pliers between the frame hardware and lens and squeeze the pliers to pry apart. The pliers are designed with a smooth form to reduce the risk of damaging lenses. Also, if positioned properly the frame finish will not be scratched. Sometimes it’s necessary to rock the pliers a little to separate completely. If you are going to reuse the lens, use the Rimless Punch to remove the bushings from both sides of each lens. Simply push both the prongs through the lens holes to ream out the debris left inside the lens holes.


Trick of the Trade

Before assembling any drilled mount, always use a beveling tool to put a slight chamfer on both sides of each hole. This helps eliminate stress on the lenses, which could contribute to cracking or crazing around the edges of the hole. Insert a new compression bushing into one of the lenses. The bushing will be extra long to accommodate almost any lens thickness. To cut it to the proper length, cut the ends of the bushing flush with the lens surface. Special round end cutters have been designed to best accommodate this step in assembly. The round tip reduces risk of lens damage and the sharp, razor like jaws are designed specifically and only for cutting these nylon bushings.

Trick of the Trade

Compression cutting pliers should have a "set screw" built into the jaw. This enables you to set the cutting depth and reduce the amount of distortion of the mounting tube. The more the tube is distorted, the more difficult it can be to insert the hardware. If the cut end of the tube is distorted, use a scribe or some pointed object to open the hole.

A scribe is the best tool for this as it has a tapered end and widens the end of the tube, aiding in hardware insertion. To assemble the insert to the barbed posts of the frame, use the rimless compression pliers to fully seat the hardware into the bushings. These pliers have a floating horizontal seat to rock back and forth as you compress the mount together. Squeeze gently until they start to fit together.

Trick of the Trade

There are many different types of compression sleeves made of different durometers of nylon. A stiffer nylon gives optimum strength but it is more difficult to get hardware inserted. Conversely, the softer the nylon, the easier to mount but holding strength could be compromised. If you don’t have OEM bushings, a medium “stiffness” is highly recommended and has proven to work very well as a replacement for OEM bushings.


When all the hardware is assembled to the lenses, final adjustments should be made in order to get the frame “bench aligned” and ready for personal patient fitting. The typical adjustments here are face form at the bridge, temple to front angles, lens propeller and pantoscopic angle adjustments.

Regardless of the adjustment you are performing, or the rimless assembly, it is best to use Rimless Bracing Pliers to protect the lenses from breaking. These pliers are designed to brace and virtually eliminate the critical stress area where hardware is anchored to the lenses. This will enable you to make any adjustment without lens damage.

The pliers are designed to seat over the hardware that passes through the lens. The front jaw of the pliers pivots to compensate for base curve. The back jaw is stable and anchors at the back of the lens. Each jaw has slots and holes so that it will work with virtually any frame design or rimless hardware fabrication.

Pantoscopic Angle/Temple Angle

Brace the outside of the lens with the pliers while making adjustments to the temple angles in any direction. Secondary pliers are often used on stiffer frame materials or tight angles. However, it is always recommended to use your fingers if you are able to.

Face Form

Brace the areas near the bridge and change the face form angles with fingers or double nylon jaw pliers. Propeller

Use two bracing pliers together to easily change propeller. Once a fairly difficult task, this is now made effortlessly with the bracing pliers.

As advancements are made in rimless hardware, so are advancements in the tools used to service these frames. Many solutions come from you or your peers through the demands of your job and the necessity to resolve issues in assembly and adjusting. These and many other rimless solutions are available in the form of DVD, CDROM or hard copy training aids through Hilco.


Improve Accuracy for Drilled Rimless Styles Precision and fit are most important when processing rimless eyewear. Using digital files that describe all the drilling features (hole width and angle, notch position) can help speed the process as well as improve accuracy. Drilling Points, from Frames Data, is a database of drilling files in VCA-standard compatible format that can be loaded into most lab management systems and drilling equipment to improve workflow. Each file is tested and verified by Frames Data technicians to ensure accuracy. Drilling Points is available as an annual subscription, with updates delivered quarterly. For more information, contact Frames Data at 800-506-2245 x7831.

This article was written by Bob Woyton, director of marketing, Hilco. For questions concerning drilled rimless techniques, contact Hilco at 800-955-6544 or visit their Web site at www.hilco.com


Labtalk June 2020