Technical Information
Step 1) Slug Cutting — The raw material size is determined by the Technical Staff and slugs are cut to length.
Step 2) Heat — There are two methods of heating slugs. Induction heating, which uses electricity through a coil that is sized very closely to the diameter of the slug being heated, and gas heating where parts are placed on a belt and fed through a furnace at a speed allowing the slugs absorb heat. In both cases the temperature of the material prior to forge is verified by an optical pyrometer which ensures your part is heated properly. (View Slug Heating video to the right.)
Step 3) Forge — A heated slug is placed onto the lower die and the press is actuated. The die halves close together to force material into the top and bottom die. The forging is then ejected from the tooling using ejector pins which push against the flash outside of the die cavity and eject the part. (View Forge video to the right.)
Step 4) Trimming — Excess material is clipped off of the forging in a trim press. A punch will force the part through a die with a sharp edge around the entire profile of the part. Clippings are returned for recycling while the part is transferred to the finishing step. (View Trimming video to the right.)
Step 5) Finishing — The different surface finishes available are blasted finish, vibratory finish, and in the case of aluminum forging, an etched finish to remove oxides from the surface.
Blasted Finish
The most environmentally friendly method is a blasted finish. This method utilizes chips recycled from the sawing operation. Chips are then blasted onto the surface of the forging. This process removes any residue from the forging process.
Vibratory Finish
Parts are placed into a machine with stainless shot and vibrated to remove residue. Parts are shiny in appearance.
Etched Finish
Aluminum forged parts can be etched which will remove oxides from the surface. This creates a bright silver appearance.
Forging Compared to Other Processes
Vs. Castings
- A casting cannot compare to a forging in strength. By working the material twice, through extrusion of the bar stock and hot working at forge. A forging has superior properties than that of a casting.
- Because the forging process is very repeatable, costs can be improved compared to a cast part. The forge process redefines grain with heat and pressure. Castings contain porosity which may cause defects not discovered until the part is machined, costing valuable time and money.
- Tooling costs for some casting processes can be prohibitive. This is especially true for medium and low volume applications. In comparison, forging tools require relatively low capital.
- During the machining operation it is very important to maintain dimensional control. Fixturing a forged part is very consistent due to the stable condition of the material and less process variability of the forging process. Reduced distortion of a forging during heat treatment is also an improvement because of material and process stability.
Vs. Machined Bar or Plate
- Forged configurations can reduce machining time, generate less scrap and lower assembly costs. Material is used where necessary and removed from areas where it is not required reducing raw material and excess machining costs. In some cases features can be incorporated into a forged design that will eliminate an assembled component and possible leak path and reduce secondary machining.
- Bar stock and plate have grain structures that run in one direction. A forging redefines the grain structure so that strength is imparted into all areas of the part. This improves the metallurgical properties of your design adding strength where bar stock cannot.
Alloy Specifications
Current Material Forged
| Alloy | Description | Comment |
|---|---|---|
| Brass and Bronze* | ||
| 2745 | No Lead Plumbing Brass | Complies with AB-1953. |
| 27451 35330 3700 |
DZR No Lead Plumbing Brass DZR Brass Low Lead Forging Brass |
For lead free compliance and dezincification resistance For dezincification resistance Used for Low Lead applications. |
| 3770 | Forging Brass | General forging use. |
| 4850 | Naval Brass High Leaded | Marine applications. |
| 6420 | Aliminum Silicon Bronze | High strength and corrosion resistant. |
| 6731 | Dynalloy Bronze Leaded | Heat treatable bearing bronze for wear application. |
| 6735 | Dynalloy Swash Plate | Used for automotive market. |
| 6741 | Dynalloy Bronze | Non heat treatable bearing bronze for wear application. |
| Aluminum* | ||
| 2014 | Aluminum and Copper | Excellent mechanical properties. Heat treatable. |
| 3003 | Aluminum and Magnesium | Moderate Strength. Non heat treatable. Brazeable applications. |
| 4032 | Aluminum and Silicon | High wearing properties. |
| 6020 | Aluminum and Tin | Suitable replacement for leaded aluminum alloys. |
| v62 SN | Aluminum and Tin | Suitable replacement for leaded aluminum alloys. |
| 6061 | Aluminum with Silicon and Magnesium | Heat treatable and medium strength. Very versatile with many applications. |
| 6063 | Aluminum with Silicon and Magnesium | Heat treatable and medium strength. Brazeable applications. |
| 6082 | Aluminum with Silicon and Magnesium | Heat treatable and medium strength. Very versatile with many applications. |
| 7075 | Aluminum and Zinc | Heat treatable and very high strength. Applications for highly stressed parts. |
| A390 | Aluminum with Silicon and Copper | Heat treatable. For highest strength applications. |
* Other materials available. Please consult Mueller with any requests.
Tech Tables
Forging Criteria
| Brass | Aluminum | |
|---|---|---|
| Draft Angles | 2-3° | 3-5° |
| Radii | 0.06 | 0.13 |
| Machining Allowance | .030 Min. | .030 Min |
| Flash Thickness | 0.04 | 0.06 |
| Flash Extension | .030 Max. | .030 Max |
Forging Tolerances
| Brass | Aluminum | |
|---|---|---|
| Linear Dimensions | ±.015 | 0.02 |
| Angular Dimensions | ±1° | ±1° |
| Radial Dimensions | ±.015 | ±.020 |
| Concentricity | .020 TIR | .030 TIR |
| Mismatch | .020 Max | .020 Max |
| Flash Thickness | 0.04 | 0.06 |
| Flash Extension | .030 Max. | .030 Max. |
| Flatness | .005/inch | .005/inch |
| Surface Finish | 63-250 rms | 63-250 rms |
*All design criteria subject to review of actual geometry. Dimensions are in inches.
Simulation Examples
Mueller Forging Company has Design Simulation capability.
This advanced technology allows our engineers to assist you in analyzing metal flow and tool stresses to create the best component for both the user and manufacturer.
- Metal flow analysis prior to tool build ensures robust design and quality.
- Tool stress analysis addresses any manufacturing issues prior to production. The result is an optimized process and smooth new product launch.