Pure Du Pont brand PTFE in a very fine powdered form, this product is a superior substitute for talc and other lubricants commonly used on grand knuckles and keybeds. The knuckle is the single biggest source of friction in the grand action. Despite graphite or polymer coatings on the repetition lever, friction levels often remain high enough to adversely affect touch weight and cause squeaking. While dry lubricants such as talc or One-Puff will work to some degree, none are as effective or long-lasting as the correct grade of PTFE powder. The average particle size is 3 microns. Available in a 1 oz, 2 oz or 8 oz jar (1 oz will treat about 12 sets of grand knuckles)
PTFE powder is especially valuable when making touchweight measurements on grand actions, since it will typically reduce friction by about 2 grams compared to other lubricants, and virtually eliminates the static friction (reluctance of the action parts to start moving), so that you no longer have to tap the bench top to get the key moving when measuring downweight or upweight. Thus the job goes faster and your measurements are more consistent.