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Industrial Material Corp
Industrial Material Corp

Understanding Certified vs. Qualified Welders

Quality can be defined as conformance to requirements; and welder certification and qualification are ways steel fabricators assure customers their specifications are exceeded or met.  A Certified Welder has passed a weld test, including visual inspection, and bend-test and/or x-ray, at an American Welding Society (AWS) Accredited Test Facility, by a Certified Weld Inspector.


All AWS Certifications are valid for six months, when the welder is required to renew (prove) his/her continuing certified welding activity.  This renewal is documented in a Continuity Log.


A Qualified Welder is one who has been tested by the fabricator, or sometimes customer, in accordance with documented requirements.  Qualification also typically includes visual inspection and a bend test.


AWS Welding Codes (for example D1.1) require qualification ‑ not certification ‑ of welders per a Weld Procedure Specification, and documented in a Welder Qualification Test Record, signed by a qualified or certified inspector.


Industrial Material Corporation’s (IMC’s) certified AWS D1.1 Structural Steel welders specialize in lighter-tonnage, and faster turn-around structural and miscellaneous fabrication.  To learn more, see IMC Fabrication.


Butt (Weld) of The Joke

Ordering Butt Weld (BW) Fittings can be tricky. BW Fittings are typically used with larger pipe sizes to connect equipment and direct flow. The most common material for carbon steel butt weld fittings is A234 WPB.


Butt Weld fittings are classified as Standard (Std) or Extra Heavy (XH), but (no pun intended) are also specified in Pipe Schedules, Sch 40, Sch 80…. However, for 12” and larger sizes, Sch 40 and Sch 80 do not correspond to Std and XH. For these sizes, if you are requesting Sch 40, you must specify if you want “True 40” or Std Wall.


Need some help finding the right pipe and fittings to purchase? Call or email Industrial Material Corporation today!

Industrial Material Corp
Industrial Material Corp


Talking the Walk(way)

People get confused when ordering bar grating, walkway grating, and expanded metal – the first two are often used in catwalks or platforms, the last should almost never be. 


  • Bar grating, supports the heaviest loads, and is a panel of flat bearing bars connected by round cross bars. Bar grating is often purchased with a serrated surface (pictured above), to reduce slips.

  • Walkway grating, on the other hand is a heavy, raised pattern (also to reduce slips) expanded metal, with the familiar diamond pattern. 

  • Expanded metal is the lightest material, often used to screen, and can be purchased either raised or flat.


Industrial Material Corp. is your steel experts! Download the IMC Steel Book or contact us at for a hard copy of your own.


Hex Tap Bolt or Full Thread
Hex Cap Screw?

Customers sometimes use the term “hex tap bolt” or “tap bolt” when they are actually looking for a “fully threaded hex cap screw”. While both have threads the entire length of the fastener, a “bolt” is a designed to be used with a nut, and a “screw” is designed to be installed by tightening the head.


Full thread hex cap screws can be identified by a washer face on the underside of the head (in the photo above, the cap screw is on the left). In the absence of a nut, the washer face ensures proper tightening. 


In the U.S., a fully threaded hex cap screw is acceptable as a hex tap bolt, but a tap bolt is not acceptable as a cap screw. This is because it lacks a washer face. The customer must understand the difference and approve the substitution of a hex tap bolt for a hex cap screw.


Industrial Material has provided high-quality fasteners to industry for over half a century! Call or email us here at IMC to purchase hex head bolts, studs and more. For additional information on the fasteners we provide, see Fastener and System Solutions.

Industrial Material Corp
Industrial Material Corp
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