Kennametal Tooling, Custom Laser Cutting, Foam Cutting, or 3D Printing? A Procurement Scenario Guide

I manage procurement for a 120-person custom machining shop. When I first started managing custom-manufacturing purchases, I assumed every job had one obvious answer: if it is metal, machine it; if it is plastic, print it. After six years of reviewing purchase orders (and a few painful audits), I stopped thinking in absolute rules. The better question is: Which scenario are you in?

This is not a lazy 'it depends' answer. Different requirements point to different process branches. Sometimes that means using a Kennametal boring bar. Sometimes it means ordering custom laser metal cutting. And sometimes the most cost-effective option is a hot tool for cutting foam or a desktop 3D printer for a one-day proof.

The Four Branch Scenarios

I group custom-part requests into four scenarios. No group is better or worse; each has a different cost structure.

Scenario 1: Bores, Tolerances, and Cylindrical Work

If a drawing calls for a hole that must be straight, round, and held to a tight tolerance, drilling alone rarely gets you there. The reliable path is a boring operation, usually on a lathe or machining center, with a boring bar and an insert matched to the material.

What most people don't realize is that a boring bar only works well if the whole setup is rigid. In this branch, I am willing to spend more than the cheapest quote for predictability. A Kennametal boring bar is not magic; it is engineered. I learned this the hard way when a 'bargain' bar produced a scrapped part after the outside vendor had already shipped the raw forging. The rework cost was several times the price difference between the two bars.

For insert geometry, I keep the Kennametal turning catalog open while reviewing prints. The catalog is the fastest way to verify shank size, insert pocket, and grade family before asking a sales engineer for speed and feed guidance.

Scenario 2: Sheet Metal Profiles and Laser Cutting

When the part is a flat outline—brackets, covers, plates, or tube-cut shapes—custom laser metal cutting often beats machining. And sometimes it beats making the part in-house, which is the part that surprises people.

It feels counterintuitive, because a CNC mill seems like the flexible option. But many laser shops run fully nested sheets with minimal manual handling. Once I add setup time, programming, deburring, and scrap risk from my own shop, a 40-piece laser job is frequently cheaper outside. The issue is not whether we own a mill; it is whether our mill is the lowest-cost way to make that specific feature.

My cost sheet for this decision includes:

• Material size and kerf loss
• Laser cutting time or per-inch price
• Setup or file preparation charges
• Deburring and secondary cleaning labor
• Inspection and rework risk
• Shipping in both directions, if outsourced

Notice that unit price is only one line, not the final decision. A quote can look lower and still lose on total cost once hidden setup is added.

Scenario 3: Foam Models and Plastic Proof-of-Concept Parts

If a project is meant to check packaging, ergonomics, or a nonstructural concept, there is no reason to start making metal chips. For low-density foam, a hot tool for cutting foam is often faster, cheaper, and cleaner than CNC. A hot wire or hot knife can shape the foam without dust, and the equipment is simple enough to keep in the lab.

For a plastic concept that needs more detail, the question I keep hearing in project kickoffs is: who makes Creality 3D printers? Creality is the Shenzhen-based manufacturer behind the Ender and CR series. Those machines are common in prototyping rooms because they are inexpensive and easy to replace. They are useful for form-and-fit checks, enclosures, and simple fixtures, but they are not a replacement for production metal cutting or injection molding.

Do not let a low-cost prototyping process make the project look low-cost in front of a customer. I once sent an unpolished 3D-printed sample because 'we are just checking fit.' The customer saw stringing and layer lines and asked whether the final parts would look that rough. The prototype was dimensionally fine, but the impression was not. When a sample represents your company, quality perception is part of the deliverable.

Scenario 4: Production Turning and Boring Quantity Runs

If an operation is a repeating production job, such as 300 or more identical parts through a CNC lathe, the calculation changes from price per tool to cost per part. A toolholder that carries over many jobs can be amortized. The real variable is insert life, cycle time, and scrap.

People often think premium tooling is expensive. Actually, unpredictable tooling is expensive. I do not start from the price page of a catalog. I short-list geometries from the Kennametal turning catalog, then ask for a test recommendation. In production, a slightly higher-priced insert that reduces chatter or lasts longer almost always wins.

That said, I would not buy premium tooling for a one-off repair part. The total-cost logic cuts both ways. Spend on quality where the customer sees the result or where scrap hurts. Do not spend where a standard specification already works.

How to Recognize Which Scenario You Are In

The best choice is not the most sophisticated process. It is the one that meets the requirement at the lowest total cost of ownership. Here is the quick check I use:

• If the core feature is an accurate cylindrical bore in metal, plan for a boring operation and start with a boring bar from a reputable line such as Kennametal. Confirm the insert in the turning catalog.
• If the geometry is flat or consistently profiled in sheet metal, get quotes for custom laser metal cutting and compare those with in-house machining.
• If the model is foam, packaging, or a large low-density mockup, reach for a hot tool for cutting foam before booking CNC time.
• If the model is a non-load-bearing plastic shape with complex geometry, a desktop printer—often from Creality—can handle early design reviews.
• If the product is a production metal component, focus on cost per good part, not catalog price.

Selecting a process by shop rate is like selecting an insert by color. The invoice number is not the full cost. Include setup, scrap, handling, delivery, and the cost of an unhappy customer.

After years of building spreadsheets, I have learned not to rank processes by price alone or by perceived sophistication. A basic process is the right choice when it satisfies requirements at lower total cost. The exception is when the output affects the customer's first impression. That is not a luxury expense; it is part of the product you are selling.