Cut Fastener Costs

Cut Fastener Costs

Here are some basic rules for maintaining high quality and cutting fastener costs

Use standard design fasteners wherever possible.
SPECIFY COLD-HAD PARTSŠfor most strength and lowest cost.

Cut variety of standard types and sizes.
Larger inventory of fewer parts means less stocking and ordering headaches, lower drilling, tapping, punching and tooling costs; avoids high cost of small quantity orders.

Use ANSI standard specifications wherever possible.
USE THESE TOLERANCES FOR ECONOMYŠ

Diameters: Frac. +.015, Dec. +.003
Lengths: Frac. +1/64, Dec. +.010
Angles: +2°
Drilled Holes: +.005

Use Class 2A and 2B thread tolerances.
Class 2A external thread to fit class 2B internal thread is the most frequently used thread tolerance. This gives a general purpose fit, providing sufficient clearance to minimize galling or seizing in driving. Also, the class 2A thread form allows for a minimum plating buildup.

USE LOW CARBON MATERIALŠ wherever possible.

USE HEAT TREATED FASTENERSŠ for more strength in smaller sizes to reduce size, weight and cost.

AVOID SHARP CORNERSŠ they increase cost.

Use multi-operation fasteners.
Fasteners can do more than just hold two parts together. They can replace an assembly operation, replace extra parts or perform other functions. Examples: thread-cutters, thread-formers, self-sealers, self-locking sems, etc.

DON¹T USE CUSTOM DESIGNED FASTENERSŠ unless no standard screw design will suffice for the job.

USE PLATED AND/OR PHOSPHATED FASTENERSŠ rather than solid expensive material to solve corrosive or surface reaction problems

USE SURFACE TREATED SCREWS FOR FASTENING NON-COMPATIBLE MATERIALSŠ minimizes galvanic action with mating parts.

ORDER MAXIMUM QUANTITYŠ to be used for certain period of time even though delivered at different times. Allow enough lead time.

Provide up-to-date drawings and specifications. Include a sample part if available.

Give fastener use and application method. Sometimes, newer, more efficient or lower cost fasteners can be recommended for economy.

The real cost of fasteners.
Purchase price is not a fasteners real cost. The full cost is "in-place" cost. That is, purchase price plus labor cost to install plus the down-time cost and added labor to replace it if it breaks or fails on the assembly line plus any replacement costs necessary in the field. REAL COST or in-place cost of a fastener can be 5 to 20 times the cost of a fastener.

Hold the REAL COST down! Order fasteners capable of doing the job they are intended fornot necessarily the cheapest.

How the experts order to save money.
The point we would like to stress is Standardization. By this we mean using standard, commonly used screw types and sizes, and also using a few varieties and sizes as possible.

A sales engineer/representative can tell you more about standardization and how it may save you many dollars in purchasing fasteners and assembly costs.

The expert fastener purchaser will also watch out for over-specifying. For example—if you know a fastener will be subjected only to mild corrosion, a plated fastener will perform just as well as one of solid brass or stainless steel, and at less cost. Tensile strength, life expectancy, vibration and weight should all be watched for over-specifying. Before a substitution is made, check with your engineering department to be sure.

Use special design fasteners.
When no standard screw design will suffice for a specific application, special, custom designed fasteners can provide great cost savings, although the initial cost of designing, tooling and testing may seem high. Two or three expensive parts can sometimes be replaced by a one piece special cold-headed fastener that has a lower in-place cost and is superior in quality. Also, special designs can be developed to save assembly time or perform more product operations.