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.
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.
Fundamentals of Industrial Coating
Industrial coating steel corrosion and significantly extends equipment life. The process begins with surface preparation, typically abrasive blasting, and the most common standards are provided by NACE and the SSPC.
Next, coatings are applied to achieve the desired performance. The final one is the “top-coat”, and any others are referred to as “intermediate.”
A specific combination of blasting and coating(s) is a “system”. Inspection ensures a system will perform as specified, and NACE is the most widely accepted inspection standard.
Industrial Material Corp. provides the highest level of certified inspection, NACE III. Visit our website and contact IMC for your next coatings project!
Holding It Together
Stud bolts are threaded rods with two nuts, used to connect pipe flanges, as well as other materials. Because Stud Bolts are such an essential component of flanged joints, they need to be ordered correctly. The bolting specifications for these studs are defined in ASTM A193.
To order a stud bolt, you need to know the grade (for example B7) to specify the material and mechanical requirements of the rod. You also need to specify the diameter and length, expressed in inches. Per ASTM, length is measured first thread to first thread. However, some businesses also order length measured end-to-end (E2E). It is important to make certain that you and your supplier agree on how the length will be measured.
In the case of pipe flanges, stud bolts are assumed to be all thread and are typically ordered with two, A194 2H (heavy hex) nuts.
Industrial Material Corp. (IMC) has provided fasteners to industry for over half a century. Call or email IMC to purchase stud bolts, headed bolts and more!
For additional information on the fasteners Industrial Material distributes, see Fastener and System Solutions.
Galvanizing VS. TSA for Corrosion Protection
Corrosion is the natural and gradual destruction of material. Two ways to prevent the corrosion of fabricated steel, pipe, vessels, and similar items, are Hot-Dip Galvanizing (HDG) and Thermal Spray Aluminum/Zinc (TSA).
Galvanizing, after cleaning, dips the material in a molten bath of zinc.
For larger quantities, HDG is more efficient and less expensive.
Thermal Spray Aluminum/Zinc, after abrasive blasting, sprays on aluminum, zinc, or an alloy of the two. TSA provides superior salt spray protection, has a higher melting point and can be painted without additional surface preparation.
Whichever corrosion deterrent you choose, we at Industrial Material Corporation are here to help! IMC supplies galvanized steel, pipe, fasteners, and more; manufactures HDG certified fabrication; and provides certified TSA coating.
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! You can also visit our website to download our Std and XH Pipe Guide with this link:
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.
Steel Beam Basics
Steel beams were first used in construction over 140 years ago, and were included as one of the many construction options in the original Play-Doh Fun Factory - you may recall the “H” shape! Knowing some basic terminology will ensure you are getting exactly what you want:
Wide Flange Beam (W) is the most common class of product. A typical Wide Flange is an W8” X 31#, where 8” is the section depth, and 31 lbs. the weight per foot.
American Standard Beam (S) are also known as “I-Beam” and has a slightly different profile than Wide Flange. A typical I-Beam is an S6” X 12.5#, with a 6” depth, and weighing 12.5 lbs. per foot.
Junior Beam (M) are essentially lighter weight Wide Flange. A typical Junior Beam is an M8” X 6.5#, with an 8” depth and only weighing 6.5 lbs. per foot.
For a booklet of beam profiles, and common sizes and dimensions, download a copy of IMC Steel & General Reference or, for hardcopy, email your contact information to email@example.com. We are here to help!
Being Dense Helps Estimate Weight!
Selling, fabricating and coating metals, Industrial Material Corp. (IMC) estimates weights using the L(ength), W(idth), TH(ickness) in inches, and following Metal Densities:
Carbon Steel: .28360 lbs.
Stainless Steel: .29170 lbs.
Aluminum: .09806 lbs.
and the formula: Weight = L x W x TH x Metal Density
For example, the weight of a 4’ x 10’ of ¼” carbon steel plate is, 48 x 120 x .25 x .28360 lbs. = 408.38 lbs. Galvanizing adds approximately 5% to the weight to a solid and 10% to a tube.
Industrial Material is here to help!