Can I Rebore Sintered Iron Coupling Hubs?

Given Lovejoy manufactures many of its standard straight jaw (L line), curved jaw (CJ), sleeve (S-Flex), and torsional (LVK & LK) coupling hubs from sintered iron (sintered ferrous powder metal) at its Downers Grove, IL facility, this is a question that comes up a lot.

Sintered iron is an extremely well proven technology for power transmission components that Lovejoy has been using extensively for more than 30 years... and the short answer is: yes. Any sintered iron hubs from Lovejoy can be re-bored or machined similar to other standard coupling hub materials (bar stock steel, forges, and cast iron) using similar feeds, speeds, cutting tools, and safety procedures. (And we know this first hand because we re-bore and machine hundreds of our own sintered iron hubs every day.)

One Major Word of Caution: Sintered iron coupling hubs ARE NOT magnesium alloy coupling hubs, and NOT to be confused with magnesium alloy hubs. At least one manufacturer does manufacturer coupling hubs from magnesium alloy (containing 85% to 96% magnesium). When subjected to significant heat (which could be introduced through machining) magnesium is a flammable metal that, once lit, cannot be put out with water or traditional carbon dioxide fire extinguishers. 

Should you find yourself with a magnesium alloy hub that needs to be machined... please take proper time to educate yourself in regards to proper machining and safety considerations of working with magnesium alloys (inclusive of pulling the manufacturer's MSDS sheet and talking with the manufacturer) prior to deciding if you really want to/are prepared to machine the hub yourself. 

Should you decide reboring magnesium isn't your thing, Lovejoy is equipped to quickly supply you with an alternative metal (sintered iron, cast iron, aluminum, or stainless steel) finished bore replacement coupling and/or a rough stock bore replacement coupling of an alternative material...  should you still really want to finish the bore yourself!
 
Recommended Follow-On Reading: To learn more about powder metallurgy in general, please read: Powdered Metal 101 for Mechanical Power Transmission Components

Powdered Metal 101 for Mechanical Power Transmission Components

 

What is powdered metallurgy?

Powder Metallurgy, or PM, is a process for forming metal parts by heating compacted metal powders to just below their melting points.

How does powdered metallurgy work?

Step 1: Blending – Powder metal is mixed with a lubricant

Step 2: Pressing – Mixture is pressed into a “green part”

Step 3: Sintering – “Green part” is thermally treated to remove lubricant & strengthen part (see image at right)

Step 4: Finishing (if required) – Strengthened part may be machined and/or steam treated

Why is powder metal used?

Cost - Powder metal is cost effective, eliminating most machining operations and scrap loss.

Versatility - Powder metal supports a wide variety of alloys, can be heat treated for increased strength, and produces excellent surface finishes.

Complex Designs - Powder metal enables the production of complex parts that would otherwise be near impossible to produce with other metalworking processes.

What type of power transmission parts can be made with powdered metal?

High strength materials extend the benefits of powder metal technology to numerous power transmission components including: coupling hubs, torque converter hubs, clutch hubs, flange hubs, clutch plates, bevel and pinion gears, pump gears, pump bodies, oil pump rotors, slide, gears, gerotors, parking brake gears, brake components, turbocharger components, pulleys, carriers, counterweights, sprockets, cam sprockets, solenoid components, axle nuts, differential cases, ABS sensor rings, U-Joint components, geometrically contoured bearings, magnetic sensors, A/C clutch hubs, flange hubs, sprockets, oil pump gears, EGR bases, exhaust flanges, clutch plates, carriers, helical & pinion gears, and levers.

For more information on powder metal, please visit the Metal Powders Industry Federation website (MPIF is a trade association) website and/or the Wikipedia page for powder metallurgy.