The effect of tolerances on Metal Fabricated and Welded products.

As a metal fabricator for over 35 years, we are painfully aware of the fact that engineers are continually tightening up their tolerance restrictions on blueprints submitted for fabrication.

It is true that metals processing equipment is ever improving and capable of some of the tight tolerances that these engineers are asking for.

Regardless of some of the equipment in this business that is capable of such tolerances, the problem remains that the Welding process itself is basically unchanged in the past 50 years or more, and that steel is still produced with just about the same shape and tolerances characteristics as it was nearly 50 years ago.

The straightness and even dimensions of stock steel often fall outside the tolerances as noted in the tolerance blocks of drawings submitted for fabrication, or manufacture.

This problem is further compounded in the process of welding which itself creates heat which further distorts the size and straightness of the steels.

We as manufacturers are always asking ourselves the question, “Does the engineer really intend us to spend extra time and money to reach these tolerance block tolerances, or do they have more wiggle room than is being indicated on the drawing.”

We can do things that will bring these welded products into tolerance.

We will stress relieve, & straighten after welding.

We will machine holes, surfaces, and cutouts after stress relieving.

The question is, and always will be. “Is it really necessary to spend all this time, extra processes, and money to achieve?”

Or, can the engineer design and tolerance drawings realistic to, and prudently achievable, to the real needs of the welded product.

Palatine Welding sales and estimating professionals are always willing to sit down with engineers, and discuss the cost and manufacturing probability of any of their welded metals projects.

Sincerely – Don Ellis – Sales /Estimator, 30 years Metals Fabrications and Welding Experience.