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Heat Treating Frames For Military Motorcycles Featuring Christini Motorcycles

Posted on June 19, 2012 by Metlab Heat Treating

Heat Treating Frames For Military Motorcycles Featuring Christini MotorcyclesChristini Technologies is a Philadelphia-based, manufacturer of custom all-wheel drive motorcycles. Known for manufacturing custom motorcycles for competition racing, Christini was recently awarded a contract to supply the Army with 450 tactical scout bikes to be used in worldwide operations.

Integral to the construction of the motorcycle and the performance of the bike is a special welded aluminum alloy frame. Because the frames are of a welded construction, they must be heat treated to restore the mechanical properties to eliminate the soft zone adjacent to the weld. It is critical for the application that the mechanical properties of the welded aluminum frame are restored to the original requirements so the frames do not prematurely fail during use. Metlab is the vendor of choice for the heat treating.

Steve Christini, owner of Christini Motorcycles explains, "During the manufacturing process of the motorcycle frame, you cut the head tube off then weld the frame. This changes the integrity of the metal. Heat treating brings it back to the correct specifications. Then a finish blast is used for aesthetics. We use Metlab because of the way they do the entire heat treating process. The parts are not contaminated and their process is a very clean process. This enhances the strength and integrity of frame."

Steve Christini
Steve Christini owner of
Christini Motorcycles

The material used in the frames is 6061 Aluminum. It is specified due to its strength, heat treatability, comparatively easy machining and weldability. Prior to heat treatment, the frames are cleaned to be free of any grease, oil or other contamination that may affect the parts. The frames are then heat treated to the T-6 condition, which consists of solution treating, or heating the parts to 985°F, holding for one hour at temperature and then immediately water quenching. Then the frames are age hardened at 350°F for 8 hours.
We have a load thermocouple that indicates when the part is up to the appropriate temperature. The soak time is dictated by the maximum section thickness.

After heat treatment, the parts are checked for hardness and conductivity to ensure that they meet the mechanical properties for properly heat treated frames. This process uses a calibrated micro-hardness tester and is carried out by trained quality control personnel.

Furnace temperature uniformity is the key to ensuring uniform mechanical properties, and the furnaces used for processing the frames are uniform within +/- 15°F in the complete work zone.
During the inspection process we make sure the mechanical properties, primarily hardness, fall into the process requirement range:

Reference MIL-H-6088, AMS 2770
Solution Treat Quenched Condition W
Age Harden- T6
80 BHN500 - min; 42 HRB; 78 HR15T, 40-50 Conductivity

Solution Treat (Condition W as quenched, T4-natural age at room temperature)
Age Harden - T6 Condition (Artificially Age Harden)

A visual inspection is conducted to determine if there are any types of defects especially around the integrity of the welds.

It is important to position the frames in the furnace so they do not distort during heat treating and also water quenching. While not the case with this particular application, Metlab heat treats certain parts for some customers who weld braces in place to keep the parts from moving. Also, for some customers where distortion is especially critical, parts are straightened before age hardening.

There is special engineering involved in the heat treat relating to the fixturing to both hold the parts and minimize distortion, as well as minimize transfer time. The parts are placed on special fixtures to keep them upright so not distortion from sagging. No special materials are needed for processing, just special equipment.

Metlab often turn parts around for Christini Motorcycles within a few days after receipt, and have given the company routine Friday to Monday service. Currently over 75 frames have been heat treated and processed by Metlab in 2011.

Mark Podob
Metlab Heat Treating

Posted in Heat Treating, Motorcycle Frame Heat Treating | Leave a comment

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Press Quench

Posted on March 30, 2012 by Metlab Heat Treating

The use of a press quench for hardening products allows for tight dimensional control of the heat treated part. The benefit is reduced post-heat treatment grinding time, resulting in significant cost savings. Parts press quenched are typically bearing races or gears. The bearing races are made from either 52100 steel or from carburizing grades of steel which have first been carburized to the appropriate case depth required for the product. Gears which are press quenched are also first carburized and slow cooled.

For press quenching parts at Metlab, parts are placed in an atmosphere controlled Rotary Hearth Furnace. The furnace atmosphere (which is endo-based) is adjusted to match the carbon content in the part to avoid carburizing or decarburization. The furnace is able to accommodate parts up to about 18 inches in diameter. The furnace hearth, which is about 48" in diameter, accommodates up to 8 pieces at a time. The parts are loaded sequentially, one at a time, with the furnace indexing an eighth of a turn between loading. Once the furnace is fully loaded, the number 8 piece is at the door, fully soaked out at the hardening temperature (1550°F) and is ready for quenching. The part is removed from the furnace by the operator using a robotic arm.

The heated part is placed in the press which consists of two conical dies; an upper and a lower die. The part is placed on the bottom die, and then, the entire bottom die moved into the quench area. A tapered top die comes down to meet the part, centering the part on the die and locking it into place. The part is then quenched using high velocity oil which flows through nozzles positioned 360° around the O.D. of the part, allowing the quenched part to take a set. Metlab Heat Treat Quench Press Picking up part
Operator picking up a bearing race which is at 1550°F,
from the Rotary Hearth Furnace using a robotically
controlled transfer mechanism.
Press Quench Move Part
Part is moved to the press quench
  Press Quench Part in Press
Part is placed on the lower die

The use of press quenching can allow for quenched and tempered product which is round and flat < 0.005", providing for significant reductions in machining times over parts which are free quenched. Cycle times for quenching parts range from 2 ¨ö to 10 minutes depending the size of the part allowing for relatively high production rates.

Mark Podob
Metlab Heat Treating

Posted in Heat Treating, Quench Press, Rotary Hearth Furnace | Tagged Metlab Heat Treating, Press Quench | Leave a comment

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Heat Treating Large Aluminum Trusses For Mooring Weather Balloons

Posted on March 28, 2012 by Metlab Heat Treating

Weather Balloon MooringsMetlab has heat treated a series of aluminum trusses used to tether aerostat balloons. The trusses, fabricated from 6061 Aluminum were placed in a rigid fixture with a 13' x 6' wide foot-print, 12' tall, developed to hold three trusses per heat treat cycle. Each truss was over 12' long. Parts were hardened by solution treating at 985°F, held for one hour, and then water quenched. They were then hand straightened over the complete span, and age hardened to the T-6 condition (350°F/10 hours). The pit furnace utilized for the thermal treatment measures 15' in diameter by 12' deep, and has a retort to allow for processing parts under inert atmospheres. The heat treated trusses comprise a section of the entire mooring assembly, which is over 24' long, used to anchor the balloons.

Metlab provides thermal processes in accordance with most military specifications, and is an approved supplier of heat-treating, black oxide, and coating services to many of the major manufacturers and Fortune 500 companies.

Posted in Heat Treating | Tagged Heat Treating, Weather Balloon Moorings | Leave a comment

Gear Solutions Magazine Features Metlab Heat Treating

Posted on February 29, 2012 by Metlab Heat Treating

Gear Solutions MagMetlab Heat Treating was founded just outside of Philadelphia in 1928, Metlab has innovation in its DNA. Originally a manufacturer of aircraft components, it began heat treating as part of the process, developing the "drop bottom" or "gantry" furnace along the way in order to minimize distortion in the delicate aluminum parts it was making. It continued developing its expertise in deep-case carburizing over the years, building huge furnaces to treat large components such as bearings and gears for the mining, industrial, and energy markets, among others, as well as for military applications. It was this history, along with its expansive capabilities, that drew the attention of two heat-treating professionals in 1998.

Among its long list or services are metal hardening, quenching, and tempering, induction/flame hardening, vacuum heat treating, annealing and protective atmosphere normalizing, carburizing, carbonitriding, nitrocarburizing, boriding/boronzing, cryogenic treatment, and heat treat stress relieving.

The company also provides metallurgical consulting supported by its fully equipped laboratory and the fabrication of special parts. It can heat treat parts from one pound to 25 tons, and having so many tools in its belt allows Metlab to address its customers most-complex challenges.

"We view ourselves as consultative heat treaters," Conybear says. "For instance, a customer came to us about 10 years ago who was having a problem with the rails inhis material handling system. He was using carbon steel, which was only lasting a year,and we suggested that he make them out of tool steel because of its excellent wear characteristics. He ended up asking us to design and manufacture the whole system, which we did, turning a $20,000 order into one worth around $300,000. But he hasn't had to replace those rails or even grind them in more than a decade now." Podob agrees, recalling another project involving a large fabricated gear used in the rolling mill of a steel plant. The manufacturer needed help controlling distortion, so Metlab joined a multi-company team in addressing the problem. "It took us about a year to arrive at our lowest-possible distortion," he explains, "and not only did it require refining the design of the gear, we also had to change the manufacturing process and sequence, and even develop special fixturing in the heat treatment cycle. This gear had a three-foot face width, a case depth in excess of a quarter of an inch, and when we were done it was round within 30 thousandths. The only downside was that they only need one of those every 10 years or so."

More capabilities were added in 2001 with the acquisition of J.V. Potero, Inc., which specialized in the protective atmosphere heat treating of small to medium size batches, induction hardening, and black oxide finishing of steel parts. The acquisition was part of a careful strategy the two partners have developed. "When Jim and I bought the company, it was primarily focused on these extremely challenging ¡®one-off' projects, and even though we're both drawn to that type of work we realized that we also need to make payroll," Podob says with a laugh. "So in recent years we've really worked hard to pull in some ongoing contract work, as well."

Still, the two men thrive on identifying solutions to the problems its customers encounter. "We're basically a job shop going from project to project," Conybear says, "so you never know what you'll find when you step out into the productionarea. What you'll see one week will be completely replaced by an entirely different range of products next week. And while it's a challenge to schedule that type of work, we spend a lot of time writing process specifications and making sure the job is done correctly from start to finish. We really pride ourselves on taking that type of approach, and I think it's something our customers appreciate as well."

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Nitriding Large Gears for Destroyers

Posted on August 5, 2011 by Metlab Heat Treating

Recently, Philadelphia Gear, A Brand of Timken Gears & Services Incorporated was awarded a contract by the U.S. Department of Defense for the supply of main reduction gears for the new Arleigh Burke Class Guided Missile Destroyers. Philadelphia Gear has been a long standing Metlab customer for over 50 years. Metlab will be helping with the heat treating of these gears.

The gears will come to Metlab's facility one at a time in specially built wooden crates. Each gear is ~ 112" in diameter by 86" tall and weighs about 20,000 pounds. There will be a total of six gears initially required for the destroyer project. The gears are a fabricated, welded construction, with the gear teeth made from a special alloy developed specifically for nitriding. Upon receipt, the gears will be cleaned and then placed in one of Metlab's two pit furnaces for nitriding. Six (6) thermocouples will be positioned on the gears to make sure that strict temperature uniformity is met. The furnaces have work zones that measure 15' in diameter by 12' deep, and 12' in diameter by 10' deep respectively. It is expected that the parts will be in the furnace for at least a week at temperature. Upon completion of the nitriding process the gears will then be sandblasted clean to remove maskant, and shipped back to the customer.

Metlab Gear NitridingDuring the course of the project, government inspectors will be on-site, monitoring the various stages of the project to ensure that processes and specifications are met to the high standards for this application. Metlab is familiar with working with these inspectors and providing them with the access and information necessary to ensure a smooth and compliant processing job. These gears are also on a time-sensitive schedule with tight deadlines.

Main Drive Gear for a nuclear submarine, similar to those referenced above, nitrided to a 0.040" case depth. Gear measures 12' in diameter by 12' tall and weighs approximately 24,000 pounds. Gear hub, bore and web faces have been masked to prevent Nitriding to allow for post heat treatment machining.

Metlab has accommodated many government and military projects including flight critical components like wire supports for aircraft carriers for the Navy. The company has the experience, facilities and resources to comply with all specifications and regulations for these projects and more.

Mark Podob
Vice President of Sales
Metlab Heat Treat

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Supplying Machine Ways

Posted on May 5, 2011 by Metlab Heat Treating

Machineway Heat TreatMetlab has shipped Machine Ways used to guide the track wheels of a precision industrial aluminum machine used for cutting wing segments and fuselage frames for commercial and military aircraft. Metlab chose A-2 tool steel as a replacement for the original cold fused flame hardened bi-metal steel design, which failed at the junction of the two dissimilar metals. The selection of through hardened A2 eliminates the need for complete replacement of the machine ways due to wear in service.

The Machine Way consists of eleven 12 foot long bars connected end to end, 2" thick by 6" wide, match ground to ¡¾ 0.003" in length, ¡¾ 0.0005" in thickness, with a maximum joint gap < 0.004" between adjacent bars. The overall Machine Way is over 130' long when installed.

Metlab was chosen to manage the entire project which involved partnering with the material supplier and grinding source to solve the unique problems presented by the Machine Way design. A2 tool steel needed to be obtained in the special length and size. Domestic material was purchased from the one source in Illinois which allowed for timely delivery.

The bars were heat treated vertically in Metlab's unique 48" diameter by 16' long vertical pit furnaces under a protective atmosphere to ensure no decarburization or oxidation. The individual bars were straightened to less than 0.050" in special fixturing provided by Metlab. Precision drilled and tapped locating holes (over 24 on the length of each bar) needed to be placed in the bars before heat treating. The use of low expansion A2 selected by Metlab allowed for predictable compensation for movement during heat treatment. The finished bars were then precision ground.

Metlab's expertise in overall project management, background in material selection, and experience with large shape heat treatment produced a dramatic improvement in the component without a sacrifice in the machine design.


Mark Podob
Vice President of Sales
Metlab Heat Treat

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Metlab Featured in News: "Don't cut gov't too deep"

Posted on April 12, 2011 by Metlab Heat Treating

Factory boss warns Congress: Don't cut gov't too deep

"I'm worried that the current over-emphasis on the deficit reduction, about which we were all concerned, could result in a fall back to recession," if Congress cuts too much, says James Conybear, director of operations at Metlab, a Wyndmoor company that provides metal-treatment services to other manufacturers. "Heavy, one-sided reductions (will) stall or reverse the recovery."

I met Conybear last week as a group of Philadelphia-area factory owners met with US Reps. Steny Hoyer, D-Md., Chaka Fattah, D-Phila., and Allyson Schwartz, D-Phila. and Montgomery. I wrote about the tough questions some of Conybear's peers had for the Democrats and for government generally.

But Conybear reminds me that US manufacturing faces tough competition from government-backed factories abroad - so this is no time for Congress to put a minimal-government ideology in front of real-world production and jobs.

How, I asked, does government best help manufacturers? Unlike many defense-dependent manufacturers, Metlab relies on Navy work for only about 5% of its sales. So exports are crucial.

US-backed free-trade agreements "make it easier for small manufacturers to ship stuff across borders." Thanks to the 1995 North American Free Trade Agreement, "it's like Canada and Mexico are part of this country now. In my mind, they should be. They are strong partners."

By contrast, China, potentially the world's largest market, "has policies (to) capture segments of industry. It's not a labor-cost issue." Energy equipment, cars, Western-style bicycles - China pays to produce and export them all, and much more. How can US companies compete without a tough State Department to push back at unfair competition?

Conybear also praised the work of the 23-year-old Delaware Valley Industrial Resource Center, a nonprofit manufacturing consulting group established by the late Gov. Bob Casey that relies on federal and state contracts, plus membership dues.

"They are one of the best things we have in Pennsylvania manufacturing," Conybear told me. "One, they provide leverage to us as small-business people" looking for guidance in boosting exports, improving processes and cutting costs. "And they give us a vehicle for communicating upward," reaching out to people in Congress, the presidential administration and state government. But in the current environment, "they are in danger of getting any support reduced or eliminated." Conybear hopes cool heads will prevail in Harrisburg and Washington.

Read more

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Heat Treating Camshafts

Posted on March 15, 2011 by Metlab Heat Treating

Recently, Metlab was awarded a contract to heat treat camshafts. The manufacturer of the camshafts target market is NASCAR racing engines, as well as specialty aircraft, marine engine and industrial engines. They also make camshafts to order, and Metlab has in fact heat treated some cams for Model T Fords and other antique cars.

These camshafts are manufactured from 8620 or 9310 steel, range in size from 1 1/2" - 3 1/2" O.D. x 24" to 72" long. The heat treating is done with the parts in the vertical position, resulting in a product which is straight within 0.005" T.I.R. Heat treatment requirements are a case depth of 0.120" minimum, and surface hardness in excess of HRC 62. Cryogenic processing in-between tempering is required to minimize retained austenite and increase camshaft performance. Metlab heat treats the product in one of its two long pit furnaces, which can handle parts up to 16' long. Metlab can comfortably heat treat up to 48 camshafts in a cycle. If straightening is necessary, this will be accomplished on one of two 100 ton presses located in-house. Normally the product turn-around is within a week or less.

Metlab Heat Treat CamshaftLoad of camshafts being removed from Metlab pit furnace after carburizing, prior to oil quenching.

Some camshaft manufactures use induction hardening for hardening the lobes of camshafts - this is for high volume, relatively inexpensive production cams where the performance is not as critical is it is for racing engines. Some camshafts are also nitrided, but again, the case depth is shallower, and this would be for less critical applications.

Carburizing tends to be more expensive than the other two processes, but again, the longevity of the product is much longer. The heat treating process is critical to ensuring a high quality finished product as well as providing longevity to the high performance camshafts. Keeping the parts within case depth, hardness and straightness tolerances are key factors in overall quality control

Metlab was selected because of their commitment to quality, turnaround time, and with deep pit furnaces capability to do long slender parts and maintain straightness. We normally process about a dozen or so cams per heat treat cycle, have the capability to process up to about 36 per load, and have been doing about 50 a month. The parts are shipped to a domestic manufacturer of camshafts who distributes them globally.

Mark Podob
Vice President of Sales
Metlab Heat Treating

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Black Oxide

Posted on January 25, 2011 by Metlab Heat Treating

Black Oxide is a chemical treatment that is applied to steel parts to create an attractive appearance and provide corrosion resistance. There are many applications throughout the metal working industries that use the process. These range from fire arms to fasteners, machine components, automotive parts, store fixtures and more.

The black oxide process is relatively inexpensive and does not affect part dimensions. There are some alternative processes such as painting, steam treating or powder spray coating. However black oxide is used when the specification calls for the part to have a dark appearance or when reflectivity is not an issue.

To achieve the black oxide finish the parts are cleaned, activated using an acid dip, then blackened in a special chemical bath, followed by an application of a thin protective wax or oil coating. The entire process takes a less than an hour.

Metlab has the capability to blacken parts in weights that range from only a few grams up to 1,000 lbs. The sizes can be as small as ¨ù inch and up to seven feet long. Examples include:

Retail: Store displays and fixtures
Automotive: Cans for oil filters
Electrical: wire strippers and cutters
Home / Garden: Tree toppers - jaws and clipping tools
Small gears: very tiny timers and electrical switches
Antique automobiles - fasteners for factory specs

Metlab Heat Treating - black-oxide part

A finished electrical tool part using black oxide treatment.

For most applications the turnaround time is usually completed in a week or less with the average being about three business days. Metlab can also accommodate specific packaging requirements such as individually wrapping parts.

Mark Podob
Vice President - Metlab

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Nitriding Surface Treatment

Posted on January 13, 2011 by Metlab Heat Treating

Nitriding is a surface treatment process that can be applied to a variety of machine components. The process provides a very hard surface while maintaining a "tough" core and tight tolerances can still be achieved. This process is applied at low temperatures so that part distortion is not an issue. Nitriding is often the final step in the manufacturing process of the part.

An alternative process is through hardening. However, this process requires higher cost material and the part must be ground to achieve final dimensions


  • Gear industry: Can be classified as a case hardening process
    • Typical hardness - Rockwell C 55 or greater
    • 0. 0.020 inches or deeper
    • Gears, shafts, spindles, machine tools
  • Rails and Machine Ways (where a wheel or roller rides on the parts)
    • Applied to the area of wear
  • Coupling industry: used to connect parts for steel mills
    • Sliding gear teeth are hardened to minimize wear
  • Plastic injection screws, barrels and molds: Nitriding parts up to 22 feet in length
  • Wind energy market - Gears and bearings vs. conventional carburizing or through hardening
    • Trying to avoid distortion

Some interesting customer examples would include nitriding submarine gears. The US military needed to harden a gear that was so large the submarine had to be built around the part. Metlab used the nitriding process on the gear which weighed 12,000 lbs.

Metlab Heat Treating - Gear Teeth before Nitriding
Large submarine gear is being prepared for Nitriding.
  Metlab Heat Treating - Overton Chicago Gear N15
Three bevel gears which have been Nitrided

Another example is the large gear that turns the turret of the Merkava tank, manufactured by an Israeli defense company. Each gear is 96 inches in diameter. Earlier gears were flame hardened, which resulted in some premature failures of the turret gear teeth. With nitriding, there has never been a single failure of the part.

Metlab provides metallurgical consulting to guide customers to the correct process to meet the required specifications. The Metlab facility has nitriding capabilities for parts that are up to 12 feet tall by 14 feet diameter or four feet in diameter by 22 feet long. It also has a small nitriding furnace, three feet in diameter by three feet long, for rush, non-scheduled production. The company services customers primarily in North America and runs the nitride furnaces twice a week, or as needed based on customer demand.

Mark Podob
Vice President - Metlab
Heat Treating - Surface Treatment - Metallurgical Consulting

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