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OVALITY and TOLERANCES

May 20th, 2014 | Posted by David Sheer in Uncategorized - (0 Comments)

There is a lot of confusion about how round a mechanical tube really is when received from the mill or even after grinding or honing operations.

Tolerance and Ovality are two completely different topics. When discussing DOM or SSID tubing, the limits are defined in ASTM specification A513 and in the sections concerning types 5 and 6, respectively.

Here’s the confusing part of it all. The spec states that ovality shall be within tolerances except when the wall thickness is less than 3% of the outside diameter. While the mean outside diameter is within tolerance there could exist additional ovality of 0.010″ (0.25mm) up to 2″, all the way to 0.065″ (1.65mm) at diameters over 12″ O.D.

Seamless is a completely different product and the chart in ASTM specification A519 is really intense with numerous exceptions and foot notes. The tolerances and ovality mostly exceed those listed in A513.

The best path to follow is to let your sales representative know the tolerance you require and how you plan on measuring it – with a 2 point or 3 point micrometer for instance. We will gladly check our stock and report the findings before entering the order thus reducing the possibility of a claim or reject.

Hope this helps!

BAR

  • SBQ: Special Bar Quality
  • TGP: Turned Ground & Polished
  • CDGP: Cold Drawn Ground & Polished
  • Q&T: Quench & Temper
  • BHN: Brinell Hardness Number
  • HRc: Rockwell Hardness – C Scale
  • HRb: Rockwell Hardness – B Scale
  • PSQ: Pump Shaft Quality
  • BSQ: Bearing Shaft Quality
  • PH: Precipitation Hardened

TUBE

  • DOM: Drawn Over Mandrel
  • CDSM: Cold Drawn Seamless Mechanical
  • HFSM: Hot Finish Seamless Mechanical
  • ERW: Electric Resistance Welded
  • I.D.: Inside Diameter
  • O.D.: Outside Diameter
  • CDBW : Cold Drawn Butt Welded
  • HSS: Hollow Structural Section
  • PVQ: Pressure Vessel Quality
  • SRA: Stress Relief Anneal

We often hear concerns over order quantities – especially when truck freight is involved. To give you an idea on how little is required for certain price brackets, here are samples of items required to reach a certain trucking break.

500# Order for Bars. 1 each ¾” x 12′; 1″, 1-1/4″, 1-1/2″ and 1-3/4″ x 24′
1000# Order for Bars. All of the above plus 1 bar each of 2″ and 2-1/2″ x 24′
2000# Order for Bars. 1 bar each at 24′ for 1″, 1-1/4″, 1-3/8″, 1-1/2″, 1-3/4″, 2″, 2-1/4″, 2-1/2″ and 3″
5000# Order for Bars. A 24′ bar of all the 2000# items plus 1 each of 3-1/2″, 4″ and 4-1/2″

500# Order for Tubes. 1 each 2-1/2″ x 2″, 3″ x 2-1/2″ and 3-1/2″ x 3″
1000# Order for Tubes. Each of the above plus 1 each 4″ x 3-1/2″ and 4-1/2″ x 4″
2000# Order for Tubes. Each of the 1000# items plus 1 length each of 5″ x 4-1/2″, 5-1/2″ x 5″ and 6″ x 5-1/2″

If you’re stocking up and need help with pricing, this is a sure way to remove some of the heavy fuel surcharges and packaging extras. We hope you find this information informative and useful for your ordering procedures. All bar and tube items are combined for total order pricing.

Our inside sales representatives, or your field sales representative, will be more than pleased to work out details on sizes required to meet quantity price breaks. Also, to assist your selection process, our on-line catalogue has been updated and lists the nominal and metric diameters of bars and tubes currently available from stock.

Your inquiries sent to sales@steelsupply.com will be responded to promptly with all lengths and shipping details listed – no hidden charges ever.

Steel Supply is made up of a diverse group of people. All of us have the same goal – to process your order as soon as possible and get it on the way to you.

OWNERSHIP: The ownership of Steel Supply has been with the same family since 1939. This stability allows us to be very consistent in our corporate thought processes.

GENERAL MANAGEMENT: In place for 45 years. Adapting to the modern trends for distribution, production and every day operations for over 4 decades.

SALES: Inside and Outside are here to help make your life easier. They will guide you through the ordering process and help you start a stocking program. Whether by telephone, fax or email, a prompt response is what you can count on.

PURCHASING: Updating the inventory daily and processing special products while keeping stock outages to less than 2%. Constantly working with mill suppliers and processors to keep costs low and continuous improvement high.

QUALITY: Maintaining the rigorous requirements of the ISO program while constantly working with Sales, Purchasing and Operations to make sure you get the best service.

OPERATIONS: Processing thousands of orders each month and holding a 98% or better shipping performance. Making sure your bar and tube randoms, cut lengths or machined pieces are to your specs and packaged to prevent damage during transit.

FINANCE: Processing your credit card purchases or open account invoices by mail or electronically. Always ready to assist with any customer service tracking or other issues.

PRECISION CHROME: Supporting Steel Supply with fast turnarounds and quality products. Making sure your honed, plated or induction hardened items meet or exceed industry standards.

All of us at Steel Supply say, “Thank You!” and we appreciate your continued patronage and loyalty.

Steel shafts that have been induction hardened, also called case hardened, go by a variety of trade names. Electreat® is the registered trade name for a family of shafting materials that have been produced for extra service piston rods or linear bearing shafts. Over the nearly half century of providing these materials, the names have been refined a bit to assist you in determining which product is best suited for your needs.

Electreat 50® describes our high strength chrome plated shafting. Items in this category range from 12mm diameter through and including 4-1/2″ diameter and are produced with a minimum yield strength of 100,000 PSI per ASTM A311, Class B. It should be noted that 4-1/2″ is the maximum diameter being produced with 100K yield.

Electreat 45® carries on the hardened shafting providing material with 75,000 PSI yield and is available in diameters from 115mm through and including 6″ diameter.

Electreat T45® is the description for much larger rounds from 160mm through and including 10″ diameter produced with 50K minimum yield strength.

All of the above are 1045/1050 grade steel with a minimum case depth of .030″ and hardness ranging from Rockwell C50 to 65.

Other hardened products include Electreat 60® which is our HRc 60 minimum linear bearing shafting made from 1060 steel and ground to a very close final diameter.

Electreat 130® is produced using our HY-130 grade (4140/4150 QTSRA) and stocked in very few diameters but readily processed using our in-house equipment at Precision Chrome.

Whichever Electreat® item you require, Steel Supply is your source for on-time shipping and quality.

The bars and tubes you order from The Steel Supply Company are probably the most inspected pieces of steel offered on the market today. While we have receiving inspections, in-process inspections, and final inspections, there remain limitations on the materials provided.

There are many essential features in steel making, processing, and distribution. Many of the processes used in industry today may alter or change the properties of the bar or tube. This results in our being unable to offer unconditional assurance that each and every bar or tube, even from the same heat lot, will be in exact conformance with one another.

Processes that could alter the properties include welding, machining, heat treating, grinding, and numerous others. Perhaps the most damage to a bar or tube occurs during the assembly or just plain misuse.

Quality issues should always be addressed prior to any process. This includes conformance to purchase order requirements, drawing tolerances, finishes and straightness, etc. Industry standards do not allow for a claim against materials once cut or otherwise processed which could alter the properties shown on our material certification.

We do not use chains on any of our products. Everything is lifted with a nylon sling. All of our machines and work stations use Teflon, or equivalent, buffering between the clamp, vise or other contact. Lathes use bronze bushing stock collets instead of jaws on steel chucks. Our technicians wear gloves so you won’t end up with greasy finger prints on the special surface finish. And, our paper tubes are lined with a coating to prevent sticking and maintain a viable amount of rust preventative on the surface.

We will gladly share information and incorporate your special packaging needs into our handling program. Please ask you sales representative or one of our inside sales staff for additional details.

Not much consideration is given to proper packaging but it should get as much attention as the product itself. All items that are machined or that have been processed with special finishes should be packaged properly so that shippers will not destroy the product. Here are some considerations:

Any tubular item that is shipped could be subject to fork lift or chain damage. The easiest way to handle a tube is to run the forks of a lift truck into the inside diameter (I.D.) and move it quickly. Another favorite way to ruin tubes is to lift with heavy duty chains and this often ruins the outside diameter (O.D.).

Bar stock doesn’t fare much better. Chains and lift trucks will often chew away at the precision surface and render the part a reject. Rolling the shaft across a cement floor isn’t any better!

Any part that has been machined or processed to a precision surface finish, bar or tube alike probably has a straightness requirement on the drawing. Improper packaging and rough handling could possibly knock this expensive part out of straightness also.

At Steel Supply, we specialize in packaging to prevent damage. All outer surface materials, whether bar or tube, are shipped in a heavy wall cardboard tube. The ends are shrink wrapped and steel strapping has a cushion placed under the clip so it doesn’t chew through the cardboard. Tubes are generally boxed. Welding caps on the end, even tack welding, can ruin the ovality especially on a thin wall tube. Machined shafts are boxed so that safety is exercised when unloading and damage by shippers is reduced to a minimum. Heavy lumber, export grade if required, is used and blocks are machined for the underside to insure straps stay in place. Screws or nail guns are used every few inches to make sure lids and end plates don’t come off with shipping abuse.

We’ll package any way you like or use our best judgment based on over 100 years experience. Either way, please consider packaging when you spec out a part.

An integral part of our quality system, and a requirement of our ISO 9001-2008 certification, calls for formal surveys to determine the levels of satisfaction we are offering you. The areas we survey include services, staff, products, etc. A heavy duty survey is performed at least each 18 months and is outsourced to our quality consultants.

Your answers are very helpful. We use this information to let all of our people know your opinions on all areas of our business. Sales uses this to determine call frequencies, inside sales representatives look at the information to make sure you’re not waiting too long and that you’re receiving all the information you need. Purchasing uses the survey data to adjust inventory levels so we always have material available. Quality records any compliments or complaints you express. Senior management reviews all the data especially how you benchmark us against others. All of this information is then reviewed during our Quality and Business planning session and we establish goals to allow us to service you better.

While all this is well and good, sometimes a visit or phone call is even better. Our goal is to offer you the best products and the highest level of service. The more we understand the process you use, and the more we can show you our processes, the better we are to eliminate bottle-necks which ultimately remove costs.

Your opinions matter! We welcome your feedback and ask you to let your field representative or any of our management team know your thoughts – even in periods when a formal survey is not being used. Your confidence and continuing patronage is deeply appreciated. Keep in touch.

Certification Terms

September 5th, 2013 | Posted by David Sheer in Uncategorized - (0 Comments)

Many of you have asked about definitions for items listed on the material certification. While there is no standard for reporting either elements or mechanical properties, Steel Supply requires full testing be performed on all of our incoming materials. This allows our inside sales representatives to let you know the properties, as well as the chemistry, on all of our items. It should be noted that different products only require certain values to be reported. If additional testing that is not available from the producing mill lab is required, we have a local source that does all of our testing and has an engineer verify the results. Here are some common terms:

Tensile Strength:
The maximum load per unit of original cross-sectional area obtained before rupture of a tensile specimen.

Yield Strength:
The stress at which a material exhibits a specified deviation from proportionality of stress and strain. An offset of 0.2% is typically used for metals.

Elongation:
The increase in length of a test specimen after rupture in a tensile test, expressed as a percentage of the original length.

Reduction of Area:
The difference between the original cross-sectional area of a tensile specimen and that of the smallest area at the point of rupture.

Brinell Hardness Test:
This test consists of forcing a ball of standard diameter into the specimen under standard pressure, and then judging the hardness by the amount displaced.

Jominy End-Quench Test:
Mostly used on alloy grades, this test heats one end to a quenching temperature and then sprays water on that end which provides a rapid rate of cooling, with progressively slower cooling all the way to the other end.

Charpy Test:
This determines the notched toughness, or impact strength, of a material – usually 17-4PH Stainless Steel but also some alloys. The test gives the energy in foot pounds required to break a standard notched specimen supported at the two ends.

These tests are defined in material standards and we’ll be happy to share any information within our capabilities. The best method for any specific requirement is to have the sample tested at the independent lab.

Meet Precision Chrome

August 13th, 2013 | Posted by David Sheer in Uncategorized - (0 Comments)

Many fluid power companies or machine shops work with affiliated companies. At Steel Supply, we work with our sister company, Precision Chrome, on a daily basis. Located in nearby Fox Lake, Illinois, Precision Chrome is both a supplier and processor for all needs, as explained below, related to fluid power and linear motion.

For nearly 50 years, Precision Chrome has evolved from a small parts chrome plating company to a specialist in hard chrome plating, centerless grinding, internal honing, and induction hardening. This group of processes supports Steel Supply, as well as external customers, in a variety of areas including quality, stock outages, and control of costs.

At both companies, the needs of customers, and the increasing demand for continuous improvement, have always been a priority and we go to extreme measures including strict adherence to any special tolerances, chrome plating thicknesses, hone tolerances, etc., to make certain these needs are met. Every detail of processing is tightly controlled and logged for verification and customer inspection requirements. Calibrated gauges are coupled with modern processing techniques to provide products that are delivered faster and better and with lower overall costs. All of these measures back up our ISO processes and eliminate or greatly reduce the shipment of bad materials.

There is a link to Precision Chrome on Steel Supply’s web site or call at 847-587-1515 for immediate attention.