Petersen Precision

Fineblanking is a specialized stamping process developed to overcome certain limitations of conventional stamping, and to create features previously obtained only by machining. Through the special design of the press and dies, the part is blanked with edges that have a finish similar to machining. Part accuracies, including flatness, profile and holes, are more exact than that of conventionally stamped parts.

Fineblanking differs from conventional stamping in quite a few ways. In conventional metal stamping a 2-part punch and die set is used. Fineblanking adds two more elements : a clamping or “stinger” plate to prevent roll-off and a counter punch to control deformation as the punch pushes through the plate. Thus, the part is smoothly removed from the strip. This fineblanking process resembles an extrusion process rather than the shearing process of conventional-stamping. This results in a part with superior flatness, smooth edges, less roll-off, and tighter form tolerances. The improved tolerance control results from die to punch clearances of 1/5 or less than that of conventional stamping. For additional information and images describing these differences in more detail, please see the technical data sheet to the right.

Creepfeed grinding offers a production method for manufacturing a wide range of 2-dimensional forms in both hard and soft materials with little to no residual stress. The traditional role of grinding has been to impart the required dimensional accuracy and surface finish to a component which has been subjected to preliminary stock removal operations such as milling or broaching. Creepfeed grinding extends grinding from this role to one which encompasses the preliminary stock removal as well as the finishing operation. Hence it provides a means for economically manufacturing precision forms on a number of different components.  Please see the tech sheet above for more information about this little known process and how it compared to standard grinding processes.

Petersen Precision was originally founded as a lapping company in 1966.  We still performs two types of lapping on metal parts; free and bonded abrasive. Bonded abrasive is akin to double disk grinding in that both sides are being processed at the same time, and parallelism is being held at the same time the sides are being made very flat. Bonded abrasive lapping does require tooling, but the costs are typically very low. Free abrasive can give you the option of only lapping one side, and typically requires little to no tooling. Typical application where lapping is required when the flatness of a part needs to be better than .001″, typically up to .0003″ depending on part geometry.  It can also be an efficient process for stock removal of small parts in large batches compared to grinding processes.  Whatever the specification, Petersen has a solution that fits your needs.

Petersen Precision has been machining parts using CNC mills and lathes since the 1980′s as a complement to the lapping and grinding services the company was founded upon.  Along with fineblanking, these technologies enabled Petersen Precision to move from a service based machine shop in the middle of the supply chain to a complete solution provider for the end customer.

Petersen Precision mills and turns all types of hard and exotic metals including Molybdenum, Inconel, Elgiloy, and Tungsten.

Petersen uses a variety of mill types, horizontal and vertical, as well as lathes and Swiss type turning machines with live tooling to tailor the most dependable and consistent process solution to each part.

Our feed through capability for the Swiss style turning centers maxes out at 1.25″ diameter, while our standard CNC lathes with bar feed capability max out at 2″ diameter.

CNC Lathes and Swiss Type Turning Centers:

• 2 Star Swiss Type CNC Turning Centers
• 1 Okuma LU-15-M-SC 4-axis Turning Center
• 1 Mazak Super Quick Turn 10MS (Cross-Drill and Back Spindle) Turning Center
• 5 Mazak Quick Turn 10 Lathes
• 1 Okuma LB-15 “Big Bore” Lathes
• 4 Hardinge Second Op Lathes 8″ Swing 27″ Bed with Bradmatic Control

Petersen Precision has both OD and Centerless grinders to meet our customers precision round bar needs.

Centerless Grinding can be performed on parts up to 4″ in diameter and up to 17″ in length while holding tolerances up to .0001″ and a surface finish of 4 Ra.

OD Grinding can be performed on bars up to 6″ in diameter.

Petersen Precision offers multiple technologies for grinding surfaces flat and parallel.  Standard surface grinding, Blanchard grinding and Double Disc grinding are available depending on the best solution based on the design intent of the part in question.  All of these processes are available for local jobbing work as well.

Blanchard grinding is ideal for large stock removal on large plates, up to 30″ square, and can achieve a 32 Ra finish when complete.

Double Disc grinding can be used on parts up to 15″ square and can hold a flatness and parallelism of .0002″/inch part length and deliver a surface finish of 16 Ra.

Surface grinding can hold a tolerance of .0001″ and deliver a surface finish of 4 Ra.  Our largest surface grinder has a bed 10 X 30″ in size.

Petersen Precision offers many specialty technologies for finishing (laser marking, ultrasonic cleaning, sandblasting) as well as specialty processes that may be difficult to locate (wire EDM, broaching, press fitting assemblies via hydraulic press).

In addition to the technologies listed, Petersen also can offer light duty manual assembly work to deliver a closer to finished article to the customer.  Please contact us with any questions regarding any special technology, whether listed here or not.

Petersen Precision has multiple deburring technologies depending on the solution required for each part and process.

At Petersen Precision we strongly believe that in order to deliver a precision solution, you also have to be able to prove your precision through inspection with enough accuracy to detect even the slightest changes in your process.

Over the years we have built an impressive collection of inspection tools that generally have capabilities far beyond our manufacturing technologies.

In addition to providing inspection data as required by our customers we are also able to offer contract inspection services. Please contact us for more details.

Inspection Equipment:

• 8 Gage Block Sets
• 10 Fowler Z-Cal Height Gages
• 1 American Optical Dual Optics Stereo Microscope 10 – 40X with 15X Eyepieces
• 10 Precision Squares
• 1 Wilson Model 5JR Rockwell Hardness Tester
• 1 Wilson Instron Hardness Tester Model C525T
• 1 Starrett Croblox Master Set
• 1 Olympus PME Metallurgical Microscope
• 1 Leco M-400 Knoop Microhardness Tester
• 1 Murphy & Miller Cold Stabilization Unit – 100F
• 1 Buehler Encapsulating Polishing System for Cross-Section Analytics
• 1 Federal Model 136B-5 Master Ring and Disc Comparator
• 3 UPI Dermitron Model D-8 Coating Thickness Testers
• 3 IBM PC-based Computers with SPC software
• 1 IBM PC-based Computer with Calibration software

Petersen Precision has its own tool room on site for the fabrication and maintenance of its fineblank dies, as well as the fabrication and maintenance of its in process fixturing for all other technologies.

The Tool Room’s equipment is kept separate from the production equipment despite sharing much of the same type of machinery.

Having this resource on site provides Petersen with a competitive advantage by controlling out tooling resource as well as providing opportunities for innovation due to the feedback between the operators and fixture designers and manufacturers.