Hudson Technologies is a leading manufacturer of deep drawn enclosures and stampings located in Ormond Beach, Florida.

Deep draw is a metalforming technique that is used to make seamless, one piece enclosures from metal with a closed end or bottom. Other descriptions for what we make are cans, cases, housings, headers and covers.

What differentiates our enclosures from fabricated enclosures is that ours are one piece - no welded corners or bottoms, no leak issues and very stable dimensional repeatability. In many cases, deep drawn enclosures are a lower cost solution to fabricated enclosures when welding costs and leak testing are considered. Additionally, deep drawn round enclosures are an excellent alternative to welded tubing, particularly were roundness and seamless construction are required.

The deep drawn solution eliminates issues associated with another method of enclosure manufacturing known as impact extrusion. The shortfall with impact extruded enclosures is that there is no draft angle along the sidewalls. This creates a challenge when assembling internal components or when using the enclosure as a mold.

Deep draw manufacturing forms metal into a seamless round, square or rectangular shape called an enclosure, or case. See video.

 

To be considered deep drawn, the height of the case is usually at least two times the diameter.  Deep drawn cases are used to enclose technology, especially in demanding environments or whenever tight tolerances and reliability are important.

 

The deep draw process starts when a flat piece of metal, called a blank or disc, is placed over a cavity called a die. A punch then forces the metal through the die, forming it into a shape.

 

These precision punches and dies are known as tooling. The tooling is set up in power presses which produce the tonnage, or energy, needed to force the material through the draw process. 

 

During the draw process the material moves into the shape of the die. The flow of material is controlled through pressure applied to the blank and lubrication applied to the die or the blank.

 

Each draw operation is a separate step and each step reduces the diameter and increases the height of the part. It may take five or more draws, also called reductions, to achieve the final shape.

 

Many factors, including material type and thickness, corner and bottom radii, and shape, determine the number of reductions required to make an enclosure.

There are certain characteristics that allow particular metals to be drawable. The key indicators are the tensile strength, yield strength and elongation - how much will it stretch or bend before it tears.  Hudson Technologies has developed the ability to draw Aluminum, Brass, Copper, Aluminized Steel, Cold Rolled Steel, Stainless Steel, Nickel Silver, MU-metal and Cupro Nickel alloys, with specialized talent to draw Titanium, Inconel, Hastalloy, Nickel and other alloys.

Many factors influence success or failure when considering a deep drawn case as an enclosure solution.

When exploring non-round shapes such as squares and rectangles, the inside corner and bottom radii are two of the most important factors to consider. Generally, there is a relationship between the desired material thickness and the requested corner radii. The general rule is the material thickness times two, equals the smallest corner radius obtainable (larger corner radii are desirable and may reduce the amount of draws). Exceptions can be made with additional draw operations to further reduce the corner radii. Caution statement - increased material thinning and adjacent sidewall bow can occur in some cases.
 
Draft or taper are inherent to drawn cases. A small amount of draft is necessary in order for the case to strip off of the punch after the draw operation. This will render the can slightly smaller on the closed end inside and larger on the open end inside. Our standard draft is .001" (.025mm) per inch of length.

Drawn cases also tend to have different material thicknesses throughout their length. The bottom of the can (closed end) is generally thicker than the sidewalls. Some materials have a tendency to thin or stretch more than others. In some cases, depending on the particular requirements, the tooling may be designed to intentionally thin or "iron" the sidewalls beyond the natural tendency. This may add more dimensional stability and a produce a more aesthetically pleasing case.

Burrs occur whenever metal is cut, trimmed or pierced. A burr can be discussed as displaced, attached material beyond the flat plane that is perpendicular to that surface. This is a result of the shearing and subsequent break of the material during the cutting/piercing process. Burr height and direction can be controlled with tooling clearances and punching direction. Our standard burr height is 10% of the pierced material thickness unless otherwise requested. Burrs can be removed through additional mechanical or chemical processes.

Work hardening, or cold working of material during the deep draw process, must be relaxed through a heatreat process known as annealing. This process occurs as an intermediate step during the forming and case reduction sequence. Annealing is a specific temperature and atmospheric environment designed to relieve stress created from cold working. Each metal type has a unique recipe of time, temperature, atmosphere, and cool down rate. Atmosphere refers to the gaseous environment used in a vacuum or forced flow furnace. Common atmospheres are Hydrogen, Nitrogen and Argon. Selected gases generally prevent oxidation of the parts and provide an intergranular cleansing. Due to the criticality of the annealing process, Hudson Technologies heat treats its parts in-house when applicable.

YES. Many customers have parts supplied with holes, slots, notches, tapped holes, inserts, screws and brackets; pressed, welded or brazed in place. Modifications can be performed using hard tooling or milling, and drilling equipment. Considerations should be made with respect to hole placement for screw and insert head clearance, proximity to a wall or radius and wall material thickness for an adequate number of tapped threads. All we need is a drawing or sketch with dimensions and tolerances and we can quote the appropriate tooling or process.  Hudson Technologies can also provide cases with paint, powder coated, silk-screened graphics and various plating types.

DFARS (Defense Federal Acquisition Regulations Supplement) is a reaffirmation of the 1941 Berry Amendment that mandates certain products that are manufactured for the US government and its suppliers who must have raw materials and/or processes provided from approved sources or countries. This is important information to provide when requesting a quote to ensure that our raw material source choices are compliant to this requirement.

RoHS (Reduction of use of Hazardous waste Substances), is a European directive that limits or eliminates the use of certain hazardous materials in the manufacture of electrical and electronic products. Some raw materials and plating types fall under restriction of use to this directive. This is important information to provide when requesting a quote so that the proper research is performed and alternatives can be offered to remain compliant.

REACH is a new European Community Regulation on chemicals and their safe use (EC 1907/2006). It deals with the Registration, Evaluation, Authorisation and Restriction of Chemical substances. The new law entered into force on 1 June 2007. Hudson Technologies' products are REACH compliant.

For low volume requests, a minimum lot charge may be assessed for catalog cans. Due to the complexity and number of operations, round, square and rectangular shapes will have different minimum lot charges. This gives you the flexibility to order as many or as few enclosures as you like for one price. Remember, standard Hudson Technologies catalog cans, including prototypes, have no tooling charges. Higher volume requests can be quoted separately for even greater savings.

Tooling is the means with which the deep draw process occurs. Tools are the hardened steel components that are designed and constructed to produce the enclosure from the sheet or coil raw material to the finished part. Tooling can be represented as an investment and in some cases a substantial one.

You can save thousands of dollars of initial investment by ordering standard sizes.  Hudson Technologies has made the tooling investment for you with our catalog line of drawn cases. Whenever possible, consider using one of our catalog (standard) round, square, or rectangular cases.  If a custom enclosure (non-catalog) is needed, we will try to utilize existing tooling during the quote and design process and only construct what is necessary to make the case unique to your need.

Draw tooling can be categorized in two ways - automated and line tooling. Volume usually determines the proper method to use.

Automated tooling packages are designed for use in progressive or transfer presses for high volume needs (annual usage of 100,000 pieces and higher). Once the dies are loaded, a finished part is produced with every stroke of the press. All of the forming operations are done in one very large press. Generally, this is a higher tooling cost and lower part price due to high speed automated nature of the process.

Line tooling utilizes a number of different presses, each carrying out a single operation of the forming process. Generally, this is lower cost tooling but higher part price due to the less automated process and slower production rates.

Simply put, the customer owns, in part or whole, the tooling that was purchased. If we use Hudson-owned tooling as part of the process, only the customer specific tooling that makes the part unique is owned by the customer.

Regardless of ownership, Hudson Technologies maintains the tooling for life, including replacement for wear, at no charge (unless a drawing change from the customer renders the tooling obsolete).

Our current policy is to render customer-owned tooling obsolete after seven years of inactivity unless we are notified of its status. At that time we will make every effort to contact the customer before a tool disposition has been determined.

When ordering standard Hudson Catalog cases, understanding several key words and phrases will help in the communication process.

• All standard catalog cases are prefixed with the letters HU or TC
Our part numbers are categorized buy their shape:
      HU2000-3000 series part numbers are round in shape
      HU4000 series part numbers are square in shape
      HU5000-7000 series part numbers are rectangular in shape
      HU8000 series part numbers are known as specials.
• TC series cases are classified as relay cases
TC cases are square or rectangular, and have unique dimensional and tolerance specifications.
• Specials are generally catalog cans with flanges
Specials may be round, square or rectangular. Some octagonal shapes can be found here.
• Plain less finish (P/L/F)
This is a standard catalog case, manufactured to our catalog dimensions without any additional modifications or plating.
• Less finish (L/F)
No plating or paint.
• Cut to
A standard catalog can that is being trimmed to a length, other than the length stated in the catalog for that specific can.
• Mod per drawing
A standard catalog can is being modified with a customer specific feature, such as hole, notch or embossment. The detail and the tolerance of the feature is indicated by the customer supplied drawing. All other catalog case dimensions and tolerances remain as stated in our catalog.
• Cut and Mod per drawing
The standard catalog case has a customer determined length and is being modified to a customer drawing. The drawing tolerances apply to these features. Hudson tolerances apply to the remaining catalog features of the case.
• Shop Order (SO)
A shop order case is a custom non-catalog case that is manufactured to a customer drawing in its entirety. In most cases the use of customer-owned tooling is used to create the part. These parts are not listed in the catalog.

The nature of the deep draw process can leave minor cosmetic imperfections on the cases. Minor scratches on the inside and outside that show no measurable material displacement would be considered acceptable.
Small surface dings or tool repair marks, including raw material flaws would be a reasonable expectation.
Slight scuffing, burnishing and surface appearance changes on any given surface are considered normal conditions.
Cleanliness - every effort is made to remove the manufacturing lubricants and processing contamination. Cleanliness would be described as free from residual oils, particles, and tack free. Surface staining or minor discoloration from rinse cycles including water deposits are normal.
Plain steel parts (Cold rolled steel) tend to rust quickly after fabrication. All efforts are made to reduce rust including intermediate application of rust preventing solutions. A slight brown/red discoloration of the material is considered normal. We will not ship rust pitted parts.

If any of the above conditions are not acceptable to your process or requirements we can, upon request, develop the manufacturing and handling process to ensure compliance to the request. We can provide a quote for this service.

In mid 2005 Hudson changed its part number identification on catalog cases. The traditional part number identifier was the HU part number, followed by the length, and the material type abbreviation.

Our Sales team will make sure that the new part number will correspond to your specific requests at the time you place an order. On a new order request, you can still identify the case using the old material abbreviation you desire. Your reply may have a new dash number in the place where the material abbreviation was; shown as a -00001, -00002 etc. Example: HU2360-1.188-SS is now HU2360-1.188-00003.

Please use this number when placing an order or making future inquiries. Not all part numbers have been converted to the new system. Your quote may show the part as a “new dash”. At the time of order the part will be assigned a new five digit number. There is no relevance to the material type and the corresponding dash number.