• Dossier on subcontracting Technical article

    How to Subcontract Sheet Metal Work on a Tight Deadline and Budget

    — Mis à jour le 15/09/22
Submitted by benoit.cantin on Mon 19/04/2021 - 12:43
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  • In a Metal-Interface survey of a representative panel of sheet metal product buyers*, 83% of prime contractors indicated that their main concerns when contacting subcontractors for fine and industrial sheet metal work, mechanical welding and boiler making, were price and lead times.

    In fact, the vast majority of subcontracting companies confirm that a tight budget and deadline are “almost always” announced from the beginning, and that over the past few years, the pressure on lead times has increased.

    Hervé Legall, OXYMAX, goes as far as saying that "clients want lead times to be as short as if the production was done in-house! And it’s our job to meet this demand…”

    In this context, buyers have to be pragmatic in order to save time in the overall process. In this article, we will share some areas to think about, based on interviews with subcontractors who experience this on a daily basis.
     

  • Be Transparent and Aware of Possible Technical Optimisations!

    You will save a lot of time and open up a constructive dialogue if you share your technical and commercial constraints with the subcontractor, for the parts or assemblies to be produced.

    Indeed, design offices are often skilled in a wide range of technical fields but tend to be unfamiliar with the production constraints of sheet metal parts. Maxime Francillon, BERARD, thus explains that “prime contractors sometimes have an ideal vision of their product, but it is not always industrially feasible or optimal from a financial point of view.”

    Military trucks
    Military vehicle - Copyright ROMAIRE

     

    Alexandre Andre-Chartier, ROMAIRE, recommends launching "a technical optimisation process before costing. This is a real weapon against relocation, and without the disadvantages of producing several thousand kilometres away.”

    "A subcontractor’s role is to use their expertise to suggest technical improvements that could optimise production times and therefore costs,” Eric Malley, ATEV explains.

    Mike Spencer, Groupe, adds that "companies come to us specifically to define their product and develop the best suited process. The aim is always to reduce costs while improving quality, often using innovative technologies.”

    Alexandre ANDRE-CHARTIER, ROMAIRE, specifies that "a review with the client/designer allows to ensure the coherence of the suggested optimisations, to consider other changes, and to validate them or not.”
     

  • A Few Possible and Frequent Optimisations in Sheet Metal and Mechanical Welding

    Production times and pricing are two interdependent issues. Indeed, reducing lead times means reducing the time required for each production step as much as possible, and therefore reducing the costs. Below is a selection of examples for optimisation:

    Cutting and Bending: Choosing the Best Process and Technology
    Denis Marguerite, MATIT, insists on "the importance of being able to choose between several cutting processes. This enables us to always choose the most optimal process between laser cutting, punching or stamping.”

    Another subcontractor shares this opinion. "Our strategy of making several cutting processes available means that, we can cut all types of materials, while always choosing the best technical and economical solutions.”

    There are also several possibilities in terms of bending, including numerically controlled press brakes, panelling machines and bending robots, each for a different type of production and part.

    Folding with a automatic panel bender
    Panel benders - Copyright MATIT

    Denis Marguerite, MATIT, gives the example of a review with the possibilities offered by panelling: "A metal locker with a painted 10/10 steel door, measuring 500 mm x 200 mm: reinforcements were added, to ensure the door is secure. Instead of this system, we have reworked the design. The door structure can be made from a single part, bent using our panelling machine.”

    Optimising Welding Operations

    Welder of a sheet metal assembly
    Welder of a sheet metal sub-assembly - Copyright Meca-Services

    Fabian Bijaczyk, MECA SERVICE, introduces this by explaining that "welding is often an area we focus on to optimise production costs. Indeed, we often get requests for over-quality, such as a continuous weld where a discontinuous one would suffice, welding certifications required due to a lack of knowledge of the regulations, etc.”

    Alexandre Andre-Chartier, ROMAIRE, gives an example: "one of our clients wanted a continuous weld for the assembly of 2 parts that did not need to be waterproof. We therefore suggested replacing the 90 cm weld seam with a spot weld. This change was approved by the client’s design office.”

    Mike Spencer, Groupe insists on "the importance of being able to choose the best technological solution to weld a part, in view of improving quality and also reducing costs. In our workshop, all welding technologies are available, even the most innovative ones such as 2 and 3 dimensional fibre laser welding with highly specialised engineers.”

    Reducing the Number and Variety of Components
    There is a lot to gain by reducing the number of components to be integrated into a project, as Denis Marguerite, MATIT, points out, such as “reduced assembly times, less purchases and the management of a simplified bill of materials that is easier to understand.”

    One common example is replacing, in certain situations, an electrical terminal that would need to be screwed or soldered, by a terminal cut directly into the part.

    Denis Marguerite, MATIT, provides some examples below from his company:
    "Instead of adding tapped inserts to a 15/10 thick steel part, we created tapped holes during the cutting phase on our combined laser-punching machine.

    Another example to eliminate hardware and simplify an assembly: we were producing a U-shaped support for a wheel. To prevent the wheel from touching the edges of the U, the client had, up until now, placed washers either side of the wheel. The assembly process, and keeping the washers in position, was particularly labour-intensive for the client! We optimised this process by making a boss, to remove the washers, directly during the cutting/punching operation. This greatly simplified the assembly process!”


    Getting subcontractors involved as early as possible, even during the design process, is therefore very useful when looking to reduce production costs, or when on a very tight budget. Metal-interface.com, the sheet metal subcontracting platform, shows on a daily basis, through buyers’ industrial projects, that a transparent and open approach is the most efficient and sustainable solution. Afterall, what do you have to lose?


    * Panel of 362 buyers interviewed between 07/09/20 and 11/09/2020.