THE UNIFIED NUMBERING SYSTEM

Are you aware of the Unified Numbering System (UNS)? This is a system that is meant to correlate the many metal alloy numbering systems that are being used in our country. I could go into a long discussion on this, but I believe that a simple table will give you enough information for now. Figure 11.1 shows you the various categories of alloys. If you look to the left of the table, you will see letters. The letters are the beginning for understanding types of alloys. For example, if a rating starts with the letter C, it is referring to copper. Seeing a letter F at the beginning of a rating indicates cast-iron.

Подпись: ► sensible shortcutTHE UNIFIED NUMBERING SYSTEMMETRIC SIZES

Подпись:Metric sizes are common in many places of the world. Plumbers in the United States still work primarily with customary measurements in terms of inches. However, you may find times when metric equivalents are useful. For this reason, I’m providing Figure 11.2

201

The first letter (followed by five digits)

Alloy category (assigned to date)

Axxxxx

Aluminum and its alloys

Cxxxxx

Copper and its alloys

Exxxxx

Rare-earth metals, and similar metals and alloys

Fxxxxx

Cast irons

Gxxxxx

AISI and SAE carbon and alloy steels

Hxxxxx

AISI and SAE H-steels

Jxxxxx

Cast steels (except tool steels)

Kxxxxx

Miscellaneous steels and ferrous alloys

Lxxxxx

Low-melting metals and their alloys

Mxxxxx

Miscellaneous nonferrous metals and their alloys

Nxxxxx

Nickel and its alloys

Pxxxxx

Precious metals and their alloys

Rxxxxx

Reactive and refractory metals and their alloys

Sxxxxx

Heat — and corrosion-resistant steels (including stainless), valve steels and iron-based “superalloys”

Txxxxx

Tool steels (wrought and cast)

Wxxxxx

Welding filler metals

Zxxxxx

Zinc and its alloys

FIGURE 11.1 ■ UNS metal family designations. (Courtesy of McGraw-Hill) for your use in comparing common measurements from the United States to metric measurements.

THREADED RODS

Threaded rods are often used to hang various types of pipe. If the size of the threaded pipe is too small in diameter and in its ability to support a proper amount of weight, the use of the rod can be very destructive. If you have a need to choose threaded rod for hanging pipe, you should find the informa­tion in Figures 11.3 and 11.4 very helpful.

Updated: 22 ноября, 2015 — 1:44 пп