Frequently Asked Questions

Here we will try to answer any questions that we feel relevant and may help you to understand our business and pre-empt any queries you may have.

Design

What is Design-Engineering?

Design-Engineering is really about making your design work in the physical world. Once you’ve created your design you will want to make sure it really works. Sometimes that might mean engineering it so that it can stand up, or take the weight of an object for example. Other times it might be adjusting the design so that your product meets additional requirements that were not originally intended.

What is Value-Engineering?

Value-Engineering is about making the product a different way to reduce costs of production or materials or both. As well as making a product cheaper it can also improve functionality and offer better value for money.

Fabrication

What quantities could you make of my product?

Dymond is geared up for medium run production, though to an extent it depends upon the complexity of the product you want fabricated. If it is a relatively simple item (like a bracket for example) we would look to produce in 100’s or 1000’s. But if you want a relatively complex product, we could produce in quantities around 10.

What is Metal Fabrication?

Metal fabrication is the term applied to the various processes used to make metal items or products out of raw material – ie pieces of metal sheet and tube.

What processes are used in sheet metal fabrication to make metal products?

The most common sheet metal fabrication process are:

  • Sheet metal cutting – including laser cutting, punching, guillotining, notching, drilling, saw
  • Sheet metal forming/bending – using press / bender
  • Welding/joining – including TIG welding, MIG welding, puddle welding and spot welding
  • Cleaning off unwanted metal – including linishing, grinding, deburring
  • Finishing – including EPC Powder coating, lacquering, Electro-plating in chrome and nickel

Is a Press-Brake the same as a Bender?

: Yes. Press-brake is the correct terminology, but both terms are used for the machine used for bending sheet metal or wire (also called forming or folding).

What is a Press-Brake used for in sheet metal fabrication?

A press-brake is a key piece of equipment used in sheet metal (and wire) fabrication as it is used to form folds or bends in the metal. It does this by applying pressure to force the metal between 2 parts of a press tool. One of the parts is a die which the metal is forced into, bending the metal against the die to form the fold or bend.

What is a bend allowance and how is it calculated?

In sheet metal fabrication, a bend allowance is the increase in overall length of a piece of sheet metal after it has been folded/bent. The reason for this is that when the metal is folded, the metal becomes stretched, like a finger when it is bent, hence the extra skin around the knuckle to allow for this. Because of this we need to make an allowance for this stretching by reducing the original length of the piece of metal by the equivalent amount as the material will be stretched. The bend allowance is used to calculate how much this will be.

For example, for 2mm thick mild steel, a bend of 90 degrees will need a bend allowance of 3.5mm, and for 2.5mm material the bend allowance is 4.5mm.

What is CNC sheet metal punching?

CNC punching is a cost-effective way to create multiple ‘cut-outs’ or holes in a sheet of metal. It is more cost-effective than laser cutting if you need a high quantity of relatively simple cut out shapes. The holes are formed when a tool punches through the metal. The tool is fitted with a die to create the desired shaped hole. At Dymond Engineering we use a turret press which has 16 tool stations which are CNC programmed to punch in the desired sequence.

What is welding?

Welding is a skilled process used to join 2 pieces of metal together. Electrodes are used to heat the metal pieces so that they become molten and join together. It is quite a skill to create the neat and strong welds that are required in the type of metal products we fabricate at Dymond Engineering.

What are the most common types of welding?

The main welding methods used in sheet metal fabrication are TIG, MIG, spot and Arc welding.

TIG means ‘Tungsten inert gas’ welding and uses a tungsten electrode to generate an electric arc that heats the metal to be joined. The weld is protected from oxidization and contaminants by an inert gas, normally Argon.

MIG means ‘Metal inert gas’ welding and uses an electrode to create an arc of intense heat which causes a significant amount of the metal to melt and run together. When melted, further material is added to the weld.

Spot welding is when two pieces of metal are clamped with a pair of copper electrodes on either side. The electrodes are forced together causing localised melting of the metal between the joint, which, along with the pressure forcing the joint together, creates the weld.

Arc Welding uses electricity to create the heat which melts the metals so that they remain joined together after cooling.  We do not offer ARC welding.

Jargon Buster

  • RSB – Rear Service Bar
  • ReBar – Reinforcement Bar
  • ERW – Electric Resistance Welded Steel tube
  • TIG – Tungsten Inert Gas
  • MIG – Metal Inert Gas
  • FSO – Flat Sided Oval tube

Powder Coating

What is the maximum size product you can powder coat?

The largest size we can powder coat at Dymond Engineering is 2000mm x 1250mm x 650mm.

What colours can my metal products be powder coated?

We can powder coat your metalwork in any colour from the RAL colour chart <link to image>.  There are 213 ‘classic’ colours ranging from white to black, with plenty in between, most of which are available in matt, satin and gloss finishes.

What is EPC powder coating?

Powder coating is the process of applying dry paint to a metal part.  Dry finishing is high-quality, durable and looks good.  Electrostatic Powder Coating (EPC) uses powder that is electrostatically charged before it is sprayed which means it is attracted to the metal on all surfaces, including the back of the item, giving better coverage.

What are the benefits of powder coating?

Powder coating gives a more hard-wearing, durable and robust finish than liquid paints.  A powder coated finish is more resistant to external conditions which reduces the risk of damage and fading.  At the same time it is also an attractive finish.

What is iron phosphate pre-treatment and what does it do?

Iron phosphate is a pre-treatment applied to uncoated steel before powder coating, creating a coating which acts as a barrier against oxidation.  This greatly improves the quality and robustness of the powder coating and increases its resistance to corrosion, making your metal products more hard-wearing and long lasting.

Should my metal product be powder coated or galvanised?

There is not generally a need for indoor products to be galvanised unless they are exposed to moisture.

Metal products used outdoors can be both galvanised and painted to increase resistance to oxidation/rust and to preserve appearance.  If appearance is not important then galvanising alone may be sufficient.

Otherwise the choice of finish depends on the required appearance of the product.