April 12, 2016by Michael Russo0



Roseville, MI — National Bronze Mfg. Co., a leading manufacturer of bronze bushings, bearings, and machined components, is pleased to announce the acquisition of a state of the art Okuma CNC Turning Center.  The high performance machinery combines pin point accuracy with state of the art automation technology to give National Bronze Mfg. a competitive advantage.  The new equipment will allow its customers to continue to experience some of the fastest turn-around times in the industry while keeping pace with ever-increasing demand.


“We are investing in technology and automation to better serve our customers.  We are making sure that, as our business grows, our customers can continue to get the highest of quality of parts as fast as possible”, says Michael Russo VP Business Development for National Bronze Mfg. Co. ” The capital investment is part of an effort to increase our manufacturing capacity in order to meet the increasing demands from both our existing and our new customers,” Russo states.


For more information regarding National Bronze Mfg. Co. Capabilities, follow the links below:







About National Bronze Mfg. Co.

National Bronze Mfg. is a leading manufacturer and supplier of bronze based products. Since 1911 National Bronze Mfg. has been one the largest manufacturers of bronze bushings, bearings, and other industrial components. National Bronze Mfg. is also a full metal service center supplying bronze, brass, and copper bar stock to manufacturers worldwide. With an expertise in copper alloy based product National Bronze Mfg. services customers in a wide variety of industries.


March 18, 2016by Michael Russo0


National Bronze Mfg. Co. is proud to introduce a new family of copper alloy products to their already diverse product line.  Effective immediately National Bronze Mfg. has become an authorized reseller of Toughmet®.  Toughmet® is a spinodally hardened Nickel Tin Bronze Alloy manufactured exclusively by Materion.  This propriety alloy has many unique features that make it a great choice for a number of demanding applications.

Toughmet® is available in both bar stock as well as completely machined components.  Follow the links below for more information on this exciting new addition to National’s vast product line.

Toughmet Bearing

Toughmet Alloy Information

Toughment 3 CX C96900

Toughmet 3 AT C72900

Toughmet Bearings


October 19, 2015by Michael Russo0


Continuous cast bronze tube is cast or manufactured with additional stock on both the ID (inner diameter) and OD (outer diameter) in order to finish to the stated nominal size.  The nominal size is the listed ID & OD size.  For example if you were to order a piece of bronze tube stock with a nominal size of 1 x 2, this means that the ID will finish to 1” and the OD will finish to 2”.  In order to accomplish this the bronze tube is cast with a pre-determined additional amount of stock on both the ID and OD.  So in reality the ID of the 1 x 2 sizes is actually slightly smaller than 1” and the OD is slightly larger than 2”.

When we speak of bronze tube tolerances we are talking about exactly how much extra stock is on either the ID and/or OD of the material.  The amount of additional stock varies by both alloy type and outer diameter size of the tube.  The below chart will help you understand the actual cast size of the most common continuous cast bronze alloys.


Tubes and Solids –  Alloys C93200, C92200, & C93700
Nominal OD Stock on ID Stock on OD
Up to 1.9999” -0.019/-0.064 +0.029/+0.039
Over 2” to 3.999” -0.019/ -0.064 +0.034/+0.044
Over 4” to 5” -0.047/-0.109 +0.055/+0.071
Over 5” to 9” -0.062/-0.158 +0.078/+0.110
Over 9” to 12” -0.078/-0.182 +0.094/+0.134
Over 12” to 16” -0.102/-0.214 +0.118/+0.166


Tubes and Solids –  Alloys C95400, C95900, & C95500
Nominal OD Stock on ID Stock on OD
Up to 3” -0.0505/-0.0955 +0.029/+0.039
Over 3” to 4.500” -0.090/ -0.145 +0.034/+0.044
Over 4.50” to 5.50” -0.100/-0.165 +0.055/+0.071
Over 5.50” to 9.00” -0.135/-0.210 +0.163/+0.213


Tubes and Solids –  Alloys C86300
Nominal OD Stock on ID Stock on OD
Up to 3” -0.0505/-0.0955 +0.029/+0.039
Over 3” to 4.500” -0.090/ -0.145 +0.034/+0.044
Over 4.50” to 5.50” -0.100/-0.165 +0.055/+0.071
Over 5.50” to 9.00” -0.135/-0.210 +0.163/+0.213


September 23, 2015by Michael Russo0

We recently added new content to our resources page.  This content is valuable technical tools, charts, and articles that can help make your job easier.  In addition to our own content we have also added a number of technical guides from our industry.  Feel free to use the content to guide you in your design and engineering of bronze based products.


View the new resources page from the following link:

National Bronze Mfg. Resources Page

September 18, 2015by Michael Russo0

Need help deciding what cast bronze alloy is best for your application?

Looking for available alternatives for hard to find alloys?

Download our newest tool the Cast Bronze Alloy Selection Chart


The selection chart list the most popular cast bronze alloys and allows you to compare their chemical and mechanical properties.  It also let’s you know how well each alloy machines.  The chart also tells you what alloys are stock here at National Bronze Mfg. so you can make better design decisions for your project.

As always feel free to contact us at anytime to speak with one of our experienced Sale Engineers to answer all of your questions and concerns.

Contact Us


August 25, 2015by Michael Russo0

Graphite Plugged Sleeve Bushings


In response to the growing demand for the graphite plugged bushing product line, we are happy to announce that the entire line of standard size graphite plugged sleeve bushings are available for purchase online at bronzebushings.com.  Hundreds of industry standard size sleeve bushings are listed in both inch and metric standard sizes.  These products are inventoried for quick shipment.

“Traditionally this was a custom product line for us, for which we did not carry any inventory and only manufactured upon receipt of an order from our customers” stated Michael Russo VP Business Development National Bronze Mfg. Co. “The growth in demand from our customers for this product line forced us to look at our stocking policy for these products and adjust to better serve our customer base” Russo states.  “By offering these products through our online store at bronzebushings.com we make the entire process even easier for our customers.  With the new offerings we are able to deliver a finished product to our customers in 1-2 days where in the past the lead time was at least 2 weeks.  Initial feedback has been very positive and we are constantly looking for new ways to raise our level of service that we offer our customers”.

graphite plugged bronze

The self-lubricating  graphite plugged bronze sleeve bushings are machined from continuous cast bronze bar stock.  They are then milled and plugged with solid lubricant graphite based plugs.  The plugged graphite bushings are great for applications where maintenance is difficult and where normal grease and oil based lubricants can burn off due to high temperatures.  The cast bronze base material gives these products stronger bearing abilities when compared to other self lubricating bronze bushings.

graphite plugged bronze sleeve bearing

The self-lubricating graphite plugged bronze sleeve bushings can be found at the following links:

Inch sized graphite plugged bronze sleeve bushings

Metric sized graphite plugged bronze sleeve bushings

May 13, 2015by Michael Russo0



Materials: C95400 Aluminum Bronze ASTM B505, Graphite Solid Lubricant Plugs

Processes: Milling, Plugging

Industry: Aerospace


This aluminum bronze bearing block has graphite solid lubricant plugs to give the component the added benefit of self-lubrication.  The graphite plugs cover 40% of the bearing surface, for added coverage (industry standard is 30% coverage). To learn more about calculating graphite plug coverage read our previous blog:

How to Calculate Graphite Plug Size

The bronze bearing block is used as a wear component in aerospace tooling.  C95400 Aluminum Bronzed is often used for wear or bearing blocks in tooling for equipment in a wide variety of industries.  The wear characteristics of C95400 Aluminum Bronze give the bearing block a longer life.




The graphite plugs reduce the need for regular lubrication and/or lubricant delivery systems.  An added advantage of graphite plugs in wear components is the ability to eliminate grooving previously needed for lubrication dispersal. For more information on wear component and/or graphite plug products, follow the links below.

Bronze Wear Plates

Plug Graphite Bearings

C95400 Aluminum Bronze


May 12, 2015by Michael Russo0

sae 863 bearing



Material:  SAE 863 Iron-Copper Sintered Powdered Metal ASTM B439 Grade 4

P/M Processes: Mixing, Compacting, Sintering, Sizing, Oil Impregnating

Machining Processes: Turning


Overview: This powdered metal bearing is manufactured as a blank via the P/M process and then finished machined in a secondary process.  The Iron-Copper powdered metal complies with the SAE standard 863 powdered metal, as well as the ASTM standard B439 Grade 4.  This base metal is a good economical choice for heavier loaded slower moving applications.  SAE 863 is often used in agriculture equipment, heavy duty machinery, and earth moving equipment.

SAE 863 Bushing

The SAE 863 bearing offers the added benefit of self-lubrication due to the oil impregnating during the final stage of the P/M process.  Often times many P/M bearings must include secondary machining due to limitations associated with the P/M process.  For more information on powdered metal bearings and SAE 863 Sintered Iron-Copper follow the links below.

P/M Process

P/M Design

P/M Styles and Applications

SAE 863 Sintered Iron-Copper Bearings


March 27, 2015by Michael Russo0


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 bronzebushings.com.  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 bronzebushings.com 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 sales@nationalbronze.com

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


March 4, 2015by Michael Russo0



That’s right, we’re expanding again here at National Bronze Mfg. Co.  This time with the addition of a brand new W.F. Wells band saw to our sawing department.  The added saw will increase our capacity and turnaround time for both our bar stock orders as well as our production machined components orders,  by decreasing the length of time it takes to prepare our bar stock for machining on our numerous CNC machining centers.


The new saw will also help prepare us for any surges of demand from our metal service customer base.  Many of these customers highly value our short lead times and quick delivery of bar stock needed for critical components.  Combined with one of the largest inventories of bronze bar stock in the US, this addition helps us solidify ourselves as one of the leading suppliers of bronze alloy bar stock in the US.


For more information on the various alloys offered here at National Bronze Mfg. follow the link below:

Bar Stock Alloys