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FASTENER HISTORY
1995 FIN – Blendulf Applies Swedish Army Advice to Fasteners

March 31, 1995 FIN – “When the map and the terrain do not coincide, chose the terrain,” Bengt Blendulf recalled reading in an old textbook when he was in the Swedish Army. He applied the advice to fastener engineers, manufacturers and distributors.

Designing and manufacturing the perfect fastener doesn’t guarantee it will perform properly on the job, Blendulf warned engineers attending Clemson University’s 7th annual Fastening Technology Conference March 29-30, 1995, in Cleveland, Ohio.

“Don’t neglect to evaluate maintenance in your design,” Blendulf advised.

Maintenance may follow the terrain rather than the map engineers planned, Blendulf advised.

He illustrated his contention by recalling his snow tires being changed. The mechanic dropped the wrench.

“How many times a day does the wrench bang the floor?” A bent and dinged wrench can damage the bolt you designed, Blendulf noted.

Richard Barrett of NASA reminded the engineers of “Mr. Badwrench’s axiom, ‘If tight is good, then tighter is better’.”

“Tightening factors also must be realistic on the maintenance level,” Blendulf said.

In addition to maintenance, engineers must “stop thinking about just the bolt. Think about the interacting of all the parts.”

“The environment must be considered for the joint, particularly working temperatures and corrosive media,” Blendulf advised.

It may be 70 degrees in the plant where a bolt is being installed in a new product, but replacement parts may be on a pipeline in Alaska or jungles in the Philippines, Blendulf pointed out. ©1995/2009 Fastener Industry News.