70 Custom Slitter Knives for Slitting 2–3 mm Hot-Rolled SUS 304 Stainless Steel

A stainless steel coil processor required 70 custom slitter knives for the longitudinal slitting of SUS 200, 300, and 400 series stainless steel grades.

The customer processed material thicknesses ranging from 0.8 to 3 mm. Among these applications, 2–3 mm hot-rolled SUS 304 was selected as the key operating condition for evaluating knife performance.

Based on the dimensions, material range, and cutting conditions confirmed by the customer, SENDA manufactured 70 slitter knives in the following size:

Ø320 × Ø230 × 15 mm

The customer installed the SENDA knives on its existing slitting line and compared them with similar knives supplied by other manufacturers.

According to the customer’s production feedback, the SENDA slitter knives delivered noticeably better overall cutting performance when processing 2–3 mm hot-rolled SUS 304.

To protect customer confidentiality, the company name, project date, and other identifying commercial information are not disclosed in this case study.

Customer Stainless Steel Slitting Requirements

The customer processed multiple stainless steel grades and thicknesses rather than one fixed material specification.

Its production range included:

• SUS 200 series stainless steel;
• SUS 300 series stainless steel;
• SUS 400 series stainless steel;
• Material thicknesses from 0.8 to 3 mm.

The main project requirements were:

Item	Project Requirement
Product	Slitter Knives
Knife Size	Ø320 × Ø230 × 15 mm
Quantity	70 Pieces
Materials	SUS 200, 300, and 400 Series Stainless Steel
Material Thickness	0.8–3 mm
Key Material	Hot-Rolled SUS 304
Key Thickness Range	2–3 mm
Application	Stainless Steel Coil Slitting

The customer was not simply looking for replacement knives that matched the installation dimensions.

It needed custom slitter knives manufactured for its material range and key cutting condition, with performance verified on the existing production line.

What Problems Did SENDA Help the Customer Address?

The customer had previously used similar slitter knives supplied by other manufacturers.

Although the knives met the required installation dimensions, their cutting performance on 2–3 mm hot-rolled SUS 304 was not necessarily the same.

In this type of stainless steel slitting operation, manufacturers commonly need to control burr formation, edge-quality variation, premature knife wear, and cutting-edge chipping.

The customer did not release separate quantitative records for each possible defect. Therefore, the following sections describe the typical production risks associated with this application.

The confirmed result from this project is that the SENDA knives delivered noticeably better overall cutting performance on 2–3 mm hot-rolled SUS 304.

1. Burr Formation, Rough Slit Edges, and Edge-Quality Variation

Slitting 2–3 mm hot-rolled SUS 304 places a higher cutting load on the knives than processing thinner strip.

If the cutting-edge condition, horizontal knife clearance, or vertical knife overlap is not suitable for the material, the line may experience:

• Excessive burr formation;
• Uneven burrs along the slit edge;
• Rough slit edges;
• Local tearing or edge rollover;
• Unstable burnished and fracture zones;
• Variation in edge quality across the coil.

A smaller knife clearance does not automatically produce a better slit edge.

Insufficient clearance can increase cutting force and the risk of contact between the upper and lower knives. Excessive clearance may allow the strip to bend and stretch further before fracture, increasing burr formation or edge rollover.

The customer therefore needed more than knives that were sharp when first installed. It needed slitter knives that were more suitable for the key material and production conditions.

2. Premature Knife Wear and Cutting-Edge Chipping

The thickness, mechanical properties, surface condition, and continuous processing load of hot-rolled SUS 304 can all affect the pressure applied to the cutting edge.

If wear resistance is insufficient, the edge may become dull too quickly, causing slit-edge quality to deteriorate over time.

If hardness and toughness are not properly balanced, high cutting loads, excessive vertical overlap, or an unsuitable tooling setup may increase the risk of micro-chipping or localized edge damage.

For this type of application, knife selection cannot be based only on the steel grade or hardness value. Other relevant factors include:

• Wear resistance;
• Cutting-edge stability;
• Resistance to chipping;
• Material thickness;
• Horizontal knife clearance;
• Vertical knife overlap;
• Arbor, Spacer, and tooling condition.

3. Material Changes and Inconsistent Performance Between Suppliers

The customer processed stainless steel from 0.8 to 3 mm across the SUS 200, 300, and 400 series.

When the material grade, thickness, or surface condition changes, the same knife clearance, overlap, and tooling settings may no longer remain suitable.

If the knives also vary in thickness consistency, flatness, edge condition, or machining quality, it becomes more difficult for operators to determine whether a cutting problem is caused by:

• The strip material;
• Knife wear;
• Horizontal clearance;
• Vertical overlap;
• Tooling assembly;
• Or variation between individual knives.

The dimensions Ø320 × Ø230 × 15 mm confirm the basic installation size. However, dimensions alone cannot prove that knives from different suppliers have the same material properties, heat-treatment consistency, dimensional accuracy, or cutting-edge quality.

The customer therefore needed to reduce the risk of purchasing knives that fitted the equipment but still failed to provide suitable cutting performance.

How Did SENDA Address the Customer’s Requirements?

 

SENDA reviewed more than the knife dimensions.

The project requirements were confirmed based on the customer’s material range, thickness range, installation dimensions, and key cutting condition.

Confirming the Knife Dimensions

The required knife size was:

Ø320 × Ø230 × 15 mm

These dimensions formed the basis for meeting the customer’s confirmed installation requirements.

However, dimensional compatibility only determines whether the knives can be installed. It does not guarantee suitable performance when slitting hot-rolled SUS 304.

Reviewing the Material and Thickness Range

After confirming the knife dimensions, SENDA reviewed the customer’s application information:

• SUS 200, 300, and 400 series stainless steel;
• Material thicknesses from 0.8 to 3 mm;
• Hot-rolled SUS 304 as the key material;
• A key thickness range of 2–3 mm;
• Comparison with knives from other suppliers under production conditions.

This prevented the project from being treated only as a drawing-copying order without considering the customer’s material and cutting requirements.

Prioritizing the Hot-Rolled SUS 304 Application

Although the customer processed several stainless steel grades, 2–3 mm hot-rolled SUS 304 was selected as the key condition for production evaluation.

During the application review, SENDA confirmed:

• The material thickness range;
• The hot-rolled material condition;
• The required installation dimensions;
• The key stainless steel grade;
• The customer’s required overall cutting performance.

The public project information does not include the material grade, hardness, flatness, parallelism, or surface-finish values of this specific knife batch. This case study therefore does not assign unverified technical values to the products.

Manufacturing 70 Custom Slitter Knives for Production Evaluation

After the application requirements were confirmed, SENDA manufactured 70 custom slitter knives.

The knives were produced according to the dimensions and processing range provided by the customer.

After delivery, the customer installed them on the existing stainless steel slitting line for production evaluation.

The confirmed comparison result applies specifically to the 2–3 mm hot-rolled SUS 304 application. It does not mean that every stainless steel grade and thickness in the customer’s full production range was tested under identical comparison conditions.

Production Result on 2–3 mm Hot-Rolled SUS 304

The customer compared the SENDA slitter knives with similar knives supplied by other manufacturers.

According to the customer’s feedback:

When slitting 2–3 mm hot-rolled SUS 304, SENDA slitter knives delivered noticeably better overall cutting performance than the knives supplied by other manufacturers.

The customer did not release quantitative measurements for burr height, processed tonnage, knife service life, or regrinding intervals.

The conclusion of this case study is therefore limited to the confirmed production feedback. It does not claim:

• A specific reduction in burr height;
• Complete elimination of rough slit edges;
• A specific increase in knife service life;
• A measured reduction in cutting-edge chipping;
• Fewer regrinding cycles;
• A specific increase in production efficiency;
• Or a quantified reduction in processing costs.

The production comparison nevertheless confirmed several important points:

• The knives met the customer’s confirmed dimensional requirements;
• The material range, thickness range, and key application were reviewed before production;
• The knives received better overall cutting feedback on 2–3 mm hot-rolled SUS 304;
• The customer reduced the risk of evaluating a Slitter Knife supplier only by dimensions and price.

What Can Other Stainless Steel Processors Learn from This Case?

When purchasing slitter knives for SUS 200, 300, or 400 series stainless steel, providing only the outside diameter, inside diameter, and thickness may not be sufficient.

To help a supplier understand your application, provide:

• An existing knife drawing or physical sample;
• Outside diameter, inside diameter, and thickness;
• The specific stainless steel grade;
• Material thickness range;
• Hot-rolled or cold-rolled condition;
• Slitting machine and arbor information;
• Current knife material and operating history;
• Photos of burrs or slit-edge defects;
• Information about wear, chipping, or frequent regrinding;
• Current horizontal knife clearance and vertical overlap;
• The edge-quality or production result you want to improve.

When evaluating a new supplier, trial knives or a small-batch trial order can provide more useful evidence than comparing quotations, material names, or hardness figures alone.

Testing the knives with the actual material and existing equipment allows you to evaluate slit-edge quality, burr formation, and operating stability under real production conditions.

Frequently Asked Questions

What Causes Excessive Burrs When Slitting SUS 304 Stainless Steel?

Excessive burrs may be associated with cutting-edge wear, excessive or insufficient horizontal knife clearance, unsuitable vertical overlap, tooling assembly errors, material thickness, or machine condition.

Replacing the existing knife with a sharper one may not solve the problem if the clearance, overlap, arbor condition, or tooling setup is also incorrect.

Why Can Slitter Knives with the Same Dimensions Produce Different Edge Quality?

Cutting performance is not determined only by outside diameter, inside diameter, and thickness.

Knife material, heat-treatment condition, hardness and toughness balance, thickness consistency, cutting-edge quality, and compatibility with the production setup may all affect the final slit edge.

Matching dimensions indicate similar installation conditions. They do not guarantee identical cutting performance.

How Can Cutting-Edge Chipping Be Reduced When Slitting Hot-Rolled SUS 304?

Knife material, edge toughness, horizontal knife clearance, vertical overlap, tooling assembly, and machine condition should be checked together.

Increasing hardness alone may increase edge brittleness. Excessive overlap, abnormal arbor conditions, or contact between the upper and lower knives may also increase the risk of localized chipping.

What Knife Clearance Is Suitable for Hot-Rolled SUS 304?

There is no single clearance value suitable for every SUS 304 coil, material thickness, and slitting line.

Horizontal clearance should be adjusted according to material thickness, mechanical properties, hot-rolled surface condition, cutting-edge condition, machine rigidity, vertical overlap, and the required edge quality.

The final setting should be confirmed through production trials.

Need Custom Slitter Knives for Stainless Steel Slitting?

If you process SUS 200, 300, or 400 series stainless steel—especially 2–3 mm hot-rolled SUS 304—you can provide SENDA with your knife drawing, physical sample, material grade, thickness range, and current cutting problems.

SENDA can review your material, equipment conditions, and key operating requirements to help confirm a more suitable custom slitter knife solution.

Submit Your Knife Drawing | Describe Your Slitting Conditions | Request a Custom Quote