First let’s get the lingo down.
Deco is what we in the industry call decorative hardware, all those knobs and pulls attached to doors and drawers whether it is furniture, kitchen or bath cabinets.

The most basic of cabinet hardware, knobs are simple and usually attached by a single screw. Types of knobs include:
T-shaped knobs: a bigger knob that is easier to grasp, very popular for aging in place remodels.
Square knobs: same measurement on all four sides, sometimes referred to as table-top knobs.
Oblong knobs: rectangular shaped knobs, longer than a T-shape.
Round knobs: spherical circular shape, includes the popular “mushroom” shape, typically 1 3/8 to 2 ½ inches in diameter.
 A pull is defined by having multiple screw holes and is often determined by the center to center (CTC) measurement. 
Bar pulls: one of the most popular types of handles; it is used most often in kitchens. The bar pull is straight rod that overhangs the feet. It may be constructed in 1 or 3 pieces.
Wire pulls: one of the best value pulls constructed of wire stock bent into a C shape.
Cup pulls: often referred to as 'half-moon pulls' because of their semi-circular shape, the cup pull can only be opened from the downward facing open end. Cup pulls CTC measurement can be up to 50% shorter than the overall length of the pull as the overhang can extend the pull design extensively. 
Appliance pulls: At least 12 inches or longer these highly specialized, meticulously crafted pulls are designed to overcome the tight vacuum seals and heavy steel of refrigerator wood panel doors.  Quality characteristics of smaller batch appliance pull production include: more material, longer production time, and larger screw threads. Secure fit, smooth feel and uniform finish are the stalwarts of good appliance pull design.
Bail pulls: a specialty pull, usually in 2 pieces, a back plate and a bail —a free swinging handle that hangs down and rest against the back plate.  Typically a classic or revival style, bail pulls rest against the drawer front and must be raised to pull open.
CTC stands for Center to Center. This is the distance from the center of one screw hole to the other.  CTC is the measurement most commonly used in deco pulls and it is the measurement listed on our web site in the product title. CTC is what you must measure when remodeling or replacing pulls once holes have previously been drilled.
Screw size: Standard deco will usually have a screw thread of 8/32 or M4. This refers to the distance between the threads. Appliance pulls will have an M6 or 10/24 screw thread that provides more strength and secure hold.