Dissecting door hardware

Door knob from the Ergo Collection of custom hardware from Martin Pierce Custom Hardware When is a door knob just a door knob?  Never!  There are several components that come together with the end result being the door knob you or your customers take for granted several times every single day.

If you were to dissect a door knob you would find:

  • Door Lever – you depress the door lever or turn the knob to activate the locking mechanism. There are springs inside the lever and knob that return it to its resting position
  • Back plate - also known as an escutcheon plate. This is the decorative metal cover that usually conceals the mechanism that allows allows the door lever to function. Each manufacturer has their own way of making the lever functional but there is a lot of commonality.  For example, the “stem” end of our door levers is cast and machined so that it is a square hole that accommodates an 8 mm square spindle. This “8mm on the square” spindle has its roots in Europe but most of the really top notch American lock companies, the premier being Accurate lock, use this configuration in their mortise locks so we have too. Alternatively the spindle can be diamond shaped and is often 7mm. One end of the spindle fits snugly into the end of the lever or knob and it is held in place by various springs, screws and clips. The other end passes through a hole in the back plate and then goes through the door into the lock regardless of whether it is a mortise or tubular lock, and then passes through to the end of the lever on the other side of the door. 
  • photo by Martin Pierce Custom Hardware

  • Rose - typically used for door knobs it is the equivalent of the back plate but, as its name suggests it is round in shape.  Many of our custom decorative roses are organic and tend to be irregular in shape.  The rose is also used to house the cylinder lock, again serving the purpose of concealing the moving parts.
  • Key plate or rose from the Lizard collection of architectural hardware from Martin Pierce Custom Hardware

    As with many items we encounter in our daily lives, you can see that an ordinary door knob is anything but ordinary and involves a great deal of creativity to make them work properly and in an attractive way.

  • If you would like to see some of the pieces shown above or view our entire collection of architectural  hardware, please visit our site at www.martinpierce.com.