Short Run / Prototype Sintered Bronze Bushing Solutions


Sintered Bushings


The powdered metallurgy process is a mass production process that can reduce costs to a level that can be startlingly low when compared to CNC machining.  An added benefit of the sintered metal bushing are the unique pores that are formed in the structure of the metal.  These pores can serve as a reservoir for lubricant, providing a passage to the bearing surface.  This unique feature adds the benefit of self-lubrication to many powdered metal bearings.  But what do you do when you want the self lubricating properties of a powdered metal bushings but in quantities lower than a mass production run? Don’t worry, there are still a couple options available for this situation, this article will outline what those options are.

Option # 1 Industry Standard Parts


Due to this difficult situation, the bronze bushing industry has developed a large line of industry standard sizes that can be used for a number of common applications.  Here at National Bronze Mfg. we manufacture these industry standards in the high volumes that lend to the P/M process and stock them in our warehouse.  This gives our customers the benefit of off the shelf availability as well as the low cost of a P/M product.

Bronze Bushing Supplier


To make things even more convenient for our customers we developed the ecommerce site  This site allows visitors to easily shop for thousands of industry standard bronze bushings that are all available for quick shipment and can be purchased in very low quantities.  For more information on click the banner below.




Option #2 Sintered Bronze Bar Stock


Industry standard sizes are great if your bushing falls within one of the standard sizes, but what if your bushing doesn’t meet those requirements. How do you get a custom powdered metal bushing in a short run or prototype quantity?  This is the reason for the development of sintered bronze bar stock.  This bar stock is manufactured via the P/M process in 6-1/2” lengths.  This is the maximum length that P/M presses can compact the bar stock while keeping the required density throughout the entire bar.  This bar stock is impregnated with oil the same way many of the sintered bronze bushings are.  Like other bronze bar stock types it can be machined to produce a custom sintered bronze bushing.  The trade off with this process is that the additional machining adds to the cost of the bushing, but for lower quantities this a great solution.

Sintered Bronze Bar Stock

We stock a variety of sizes of sintered bronze bar stock here at National Bronze Mfg. and offer our customers either the bar stock itself or a custom bushing completely machined from the bar stock.  The choice is up to you, depending on your capabilities.  This process is generally much faster than the standard lead time for production runs of P/M bushings.

We offer bar stock and custom bushings in standard SAE 841 Oil Impregnated Bronze, SAE 863 Sintered Iron-Copper, and Dri-Plane dry lubricated high temperature bronze.  The Sintered bronze bars are produced to ASTM standards and have stock on the ID and OD to permit machining to the nominal dimension desired.


BB-16 Sintered Iron-Copper Bearings


BB-16 Bushings


In addition to the above mention alloys we can manufacture a heat treated BB-16 bushing.  This self-lubricating bushing is similar to the SAE 863 product, but heat treated to a particle hardness greater than Rc50.  The BB-16 bushing has a high compressive strength for extreme load, low speed reciprocating an oscillating applications. Typically used in off road equipment, backhoes, graders and earth moving equipment, this bushing requires a hardened steel shaft. Physical and Mechanical properties of the BB-16 Sintered Iron-Copper Bushing are below:


Density (gm per cu. Cm)

6.0 – 6.5

Porosity (% oil by vol.)

18.0 min.

“K” Strength Constant

62,000 psi

Elongation (% in one inch)


Tensile Strength (psi)


Yield Strength in Comp. (psi)


Apparent Hardness (Rockwell B)

70 min

Particle Hardness (Rockwell C)


Recommended Shaft Hardness


BB-16 Bearings


As with all of our products the best way to get a quote is to complete our RFQ form or email you requirement to

Our experienced sales technicians will look at your specific application  and offer a customize solution based on your needs.  For any further questions contact our sales staff via email or toll free at 800-875-3558


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