Why Small Diameter Sheet Metal Cones Are a Big Challenge & How Polder Engineering Solves It

Bhavin Solanki
Jul 7
4 min read

Cone rolling machine forming 40 mm diameter stainless steel cones with finished cones beside — SPM designed to roll 40 mm diameter cones using 6 mm thick stainless steel at a 60° angle.

The Untold Challenge in Small Diameter Sheet Metal Cones

In the world of sheet metal fabrication, not all cones are created equal. While large and medium diameter cones are common across industries, small diameter cones present a unique challenge a challenge most manufacturers shy away from.

At Polder Engineering, we've turned this niche into our strength

Small Diameter Sheet Metal Cones Forming for Sheet Metal Industries

What Are Small Diameter Cones?.

Small diameter cones typically have:

Base diameters under 150 mm
Taper angles that require precision
Wall thickness tolerances under 0.5 mm

These are commonly used in:

Jet engine nozzles
Exhaust reducers
HVAC systems
Aerospace ducting
Industrial filtration

Why Most Sheet Metal Companies Avoid Them

The tight tolerances and steep curves required in small diameter cones demand:

Advanced tooling
Skilled operators
Perfect pre-bending
Precision welding or seamless joining

Most sheet metal fabricators lack the specialized equipment or consistent process control to handle such components, leading to:

Wrinkling
Material thinning
Inconsistent curves
Time loss and material waste

Common Use Cases and Industries

Aerospace: Jet engine exhausts, rocket nozzles, cone-shaped diffusers
Automotive: Custom turbo systems, exhaust system reducers
HVAC & Ventilation: Precision ductwork with tight clearance
Defense & Military: Directional flow control components
Energy & Nuclear: Thermal shielding cones, pipe reducers

Polder Engineering serves industries where failure is not an option.

Technical Challenges in Forming Small Diameter Cones

Here are the top challenges that make small cones complex:

Polder Engineering's Advanced Capability

At Polder Engineering, we don't just make small cones — we engineer them.

✔️ Custom-built conical rolling machines

✔️ CNC-controlled forming for accuracy

✔️ Expert pre-bending and edge trimming

✔️ MIG, TIG, and laser welding for ultra-fine finish

✔️ High repeatability for batch production

Our in-house design + forming approach ensures perfect transition from drawing to finished part.

Tooling and Machinery That Make the Difference

We’ve invested in tools specifically for small cone manufacturing:

4-Roller CNC Cone Rolling Machines: For consistent forming with no gaps
Edge-Cutting Stations: To ensure 100% match before welding
Laser Seam Finders: For precision joint prep
Custom Mandrels: For accurate roundness during welding

Polder Engineering’s equipment is custom-calibrated for diameters under 100 mm — a range where others fail.

Case Studies from European Clients

🇺🇸 Case Study: Food Processing Machinery Manufacturer – USA

Client Profile: Leading OEM of hygienic stainless steel equipment for the food processing industry.

Problem: Their local suppliers were unable to deliver precisely formed small diameter cones that met hygienic and structural requirements, particularly in 304-grade stainless steel with tight tolerances.

Solution: Polder Engineering supplied a custom-built iAEHM-4R-L1300-DX cone rolling machine to their in-house fabrication shop in the USA,

capable of:

Forming cones as small as 60 mm diameter with Roller Length of 1300 mm.
Maintaining consistent surface finish suitable for food-grade applications
Automtic Forming Machine with intuitive HMI controls

Result:

✅ 80% reduction in cone forming time

✅ 100% pass rate in final assembly tests

✅ Improved hygiene compliance and equipment finish

🇸🇰 Case Study: Brewery Equipment Manufacturer – Slovakia

Client Profile: A growing Slovak company producing stainless steel brewery tanks, silos, and custom fermentation units.

Problem: Their team faced frequent delays and reworks due to manual cone forming, especially for tight-taper small diameter cones required in outlet pipes and vents.

Solution: Polder Engineering supplied a specialised SPM-4R-L350-D60 cone forming machine, tuned for precision forming of short-height, narrow-bottom cones for brewing vessels.

Result:

✅ Cut production time per cone from 24 Minutes to 6 minutes

✅ No more wrinkling at small ends with 6 mm thick cone with 40 mm diameter and 60 angle

✅ Scaled up production to meet increased export demand in EU

Quality Standards & Material Handling

We comply with:

2006/42/EC – Machinery Directive
2014/35/EU – Low Voltage Directive
2014/30/EU – Electromagnetic Compatibility (EMC)
EN ISO 12100 – Risk assessment and design safety
EN 10088-2 – Stainless steel grades and tolerances
ISO 3834-2 – Weld quality and inspection

Materials we commonly handle:

Stainless steel (304, 316, 409)
Mild steel
Inconel (for high-temp applications)
Aluminium alloys

FAQs About Small Diameter Cone Manufacturing

Q: Can you work with 0.5 mm stainless steel?

~ Yes, using precision rollers and special clamps.

Q: Can cones be delivered welded or un-welded?

~ Both options are available depending on your assembly needs.

Q: What's the max wall thickness?

~ up to 2 mm For Diameter under 30 mm

~ Up to 5 mm for diameters under 50 mm.

Q: Do you ship across Europe & United States ?

~ Yes regular shipments to Germany, Poland, Slovakia, Slovenia, Lithuania, United States, United Kingdom, Australia, Belgium, and More.

Why Manufacturers Choose Polder Engineering

✔️ In-house forming and welding = faster turnaround
✔️ Experience with aerospace and defense-grade requirements
✔️ Small batch to high-volume production
✔️ Direct consultation with design engineers
✔️ Seamless logistics across the EU

Our clients trust us not just for the product but for the process reliability and problem-solving capability.

How to Send a Drawing for Quotation

Getting started is simple:

📧 Email your drawing (PDF, DWG, STEP) to info@polder-engineering.com

💡 Include:

Cone dimensions (top/bottom diameter, height, thickness)
Quantity ( Incase of Forming Service )
Material specification
End application (if relevant)

You’ll receive a quick reponse like within 60 Minutes.

Small diameter cones aren’t just small parts they’re big challenges that can make or break your final assembly. While many sheet metal shops avoid them, Polder Engineering specializes in this complex domain.

Whether you're in aerospace, automotive, HVAC, or energy we ensure your cone components are formed right the first time.