Materials:

We offer two material choices: Brass, which is the most common choice, and copper. We do not recommend tin-plated mild steel or tin-plated brass due to the higher soldering temperatures of the tin, and poor corrosion resistance due to exposed edges. Tin-plated mild steel is plated at the mill before the cutting process, leaving all edges with exposed steel after punching, thus allowing for corrosion and cold solder joints. According to Kester Solder "Electroplated tin on steel or brass affords good protection for a while, but after three months under normal environment, tin platings are generally ineffective". This is a direct quote from Kester Solder hand book on "SOLDER ... its fundamentals and usage" under the heading of "The Problem of Solderability". The problem being, tin oxide starts to build up on the surface the day the steel is plated allowing a three-month window for the mill to sell the tin-plated steel, the shield producer to inventory it, process the shielding, and ship it to the end user before it is soldered onto a board. This time delay forces the end user to use more aggressive fluxes and higher temperatures to achieve a good solder joint on the tin-plated steel.

Nickel is our customer's plating of choice. It offers excellent solderability with a lower soldering temperature than tin, mirror like finish, and resistance to staining. Nickel-plated shielding with logos and part numbers gives your product a very clean and professional appearance.

In exceptionally sensitive areas, we recommend silver plating. It has a light gray matte finish, with excellent conductivity, solderability, and low soldering temperature.

It is recommended that all shielding be plated after cutting, thus encapsulating the part and preventing exposed edges.

Material cost is not an issue. The difference between tin-plated steel, and nickel-plated brass or copper is negligible. Our customers to date prefer brass as their main material of choice. We purchase the highest quality brass by the ton from the mills in Germany. The advantages of brass and copper, and the ability to encapsulate the product with nickel-plating produce the ideal combination for RF shielding.

Due to the softness of copper, it is only used for special cases when your engineers require it.

Tin plated mild steel is only recommended in situations where magnetic shielding of transformers and small motors are an issue.

Seventeen years of experience has shown us that with the constant change in circuit board technology, the standard material thickness and physical size of shielding is getting smaller and more complex. Material thickness started years ago at 0.020 inches and has gone as low as 0.004 inches in the recent months. The standards are 0.016 Brass for shields larger than one square inch, and 0.008 Brass for shields that are smaller.

All shields are nickel plated unless otherwise stated by the customer.

The design is up to your imagination. We will attempt to accommodate your needs and advise you on the best means to achieve them.

Size limitations: The only size limitation is due to cost, and that break point is 6 inches by 6 inches. Our methods are not cost efficient when you reach 6x6 inches, unless the shield is very detailed.
Logos: Company logos can be engraved into any surface of the shield. Tuning holes can be labeled, or any other information engraved on the shield at no extra cost.
Part numbers: Part numbers should be placed on the part somewhere, either on the inside or the outside of the shield. Experience has taught us to keep the people in the inventory department happy. Part numbers do not cost extra so DON'T FORGET THE PART NUMBER!
Internal walls: Internal walls will normally include two feet about 0.03 to 0.04 inches wide, and a means to interlock with the sidewalls or each other. Fold lines can be incorporated into the walls to allow 90 degree bends at the exact same location each time. When more than one wall is included in a set, our practice is to incorporate them into one fret to prevent losses and damage.
Lid locking methods: At present we use two different lock methods: The dimple and hole method. The twist lock method.
Computer file: The preferred file format is Acad DWG or DXF from AutoCAD. At least one dimension must be on the drawing to check scale.