D=0.5* pitch+clearance

Middle diameter = large diameter-0.5p..

Small diameter = large diameter -2h

Tooth tip width = 0.366p

Tooth root width =0.366P-0.536* clearance.

Optimum value of three needles =0.5 18P.

Three-needle reading = middle diameter +4.864* three-needle diameter-1.866p.

Formulas, in mathematics, physics, chemistry, biology and other natural sciences, use mathematical symbols to express the relationship between several quantities. It is universal and applicable to all similar problems. In mathematical logic, a formula is a formal grammatical object to express a proposition, but the proposition may depend on the free variable value of the formula. The precise definition of a formula depends on the specific formal logic involved, but there is a very typical definition (for first-order logic): the formula is defined relative to a specific language; That is, a set of constant symbols, function symbols and relational symbols, in which each function and relational symbol has an arity to indicate the number of parameters it accepts.