1018 vs. 4140 Steel: What Steel Is Best For Your Parts?

Are you tired of picking the wrong steel for your machined parts? Many manufacturers face this big problem when choosing between 1018 and 4140 steel. Picking the wrong material can lead to parts that break too soon, cost too much money, or take too long to make.

At Istar Machining, we know how hard this choice can be. We see customers waste thousands of dollars on failed parts because they picked the wrong steel. But don’t worry! We’re here to help you make the right choice for your next CNC machining service.

Let’s look at what makes these steels different and when to use each one.

What Are 1018 and 4140 Steel?

First, let’s learn about these two popular steels:

1018 Steel: The Easy-To-Work Steel

1018 steel is a low-carbon steel. This means:

• It has about 0.18% carbon
• It has 0.60-0.90% manganese
• It’s very easy to weld
• It bends well without breaking
• It’s cheap and easy to find

4140 Steel: The Strong Steel

4140 steel is a chromium-molybdenum alloy steel. This means:

• It has more carbon (about 0.40%)
• It has special metals added (0.80-1.10% chromium, 0.15-0.25% molybdenum)
• It’s much stronger
• It can be heat treated to get even stronger
• It costs more than 1018

How Different Are They? Key Properties Compared

Let’s see how these steels compare in a simple table:

This shows that 4140 is more than twice as strong as 1018! But 1018 can bend more without breaking.

What’s In These Steels?

The metals that make up each steel are very different:

The extra metals in 4140 are what make it so much stronger.

The Big Problem: Choosing Between Strength And Cost

Here’s where many companies have trouble. Should you pick:

1. 1018 steel: Easy to work with and cheap, but not very strong
2. 4140 steel: Very strong, but costs more and is harder to work with

If you pick wrong, you might face:

• Parts that break too soon
• Wasting money on steel that’s stronger than you need
• Production delays because the steel is hard to machine

How To Choose The Right Steel For Your Project

At Istar Machining, we help you make this choice easy. Here’s how to pick:

Choose 1018 Steel When:

• You need low-cost parts
• Your parts won’t be under high stress
• You need parts that are easy to weld
• You’re making simple frames or fixtures
• You need to bend or form the parts
• You need to make many parts quickly

Choose 4140 Steel When:

• You need high-strength parts
• Your parts will face heavy loads
• You need parts that won’t wear down fast
• You’re making gears, axles, or shafts
• Your parts need to be heat treated
• Your parts will be used in tough conditions

How Each Steel Works In Different Jobs

Let’s see where each steel is best used:

The Cost Difference

Money matters! Here’s what you can expect to pay:

This means 4140 can cost 2-3 times more than 1018 for the same part!

Heat Treatment: A Big Difference

One of the biggest differences is how these steels can be made stronger with heat:

1018 Steel Heat Options:

• Usually not heat treated
• Can be case hardened (only the outside gets hard)
• Stays soft in the middle
• Simple to heat treat

4140 Steel Heat Options:

• Often quenched and tempered
• Gets 40% harder after heat treatment
• Strong all the way through
• More complex heat treatment

Machining Differences: Which Is Easier To Work With?

If you’re using CNC milling or CNC turning, the steel you pick matters a lot:

1018 Steel Machining:

• Easy to cut
• Uses less tool wear
• Faster cutting speeds
• Simple to set up
• Great for rapid CNC machining

4140 Steel Machining:

• Harder to cut
• Wears out tools faster
• Slower cutting speeds
• Needs more skill to set up
• Better for precision CNC machining

Welding: A Critical Difference

If you need to weld your parts, pay close attention:

1018 Steel Welding:

• Very weldable
• No special steps needed
• Low risk of cracking
• Can be welded with basic equipment

4140 Steel Welding:

• Much harder to weld
• Needs pre-heating
• Needs post-weld heat treatment
• Higher risk of cracking
• Needs expert welders

Real-World Examples

Let’s look at two real customers who faced this choice:

Case Study 1: Auto Parts Maker

A car parts maker was using 1018 steel for engine brackets. The brackets kept breaking under stress. When they switched to 4140 steel, the parts lasted 5 times longer but cost 30% more. The better durability was worth the extra cost.

Case Study 2: Tool Fixture Maker

A tool maker was using expensive 4140 for simple jigs and fixtures. By switching to 1018, they cut costs by 40% with no loss in performance since the fixtures didn’t need high strength.

The Solution: Expert Help From Istar Machining

At Istar Machining, we solve this problem every day. Our experts will:

1. Look at your part design
2. Ask about how the part will be used
3. Consider your budget
4. Suggest the best steel option
5. Machine your parts with precision
6. Deliver on time, every time

With our custom CNC machining services, you don’t need to become a steel expert – we are!

Key Things To Remember

When picking between 1018 and 4140 steel, remember:

• 1018 Steel: Less strong, easy to work with, cheap, good for simple parts
• 4140 Steel: Very strong, harder to work with, more expensive, best for critical parts

FAQ About 1018 vs. 4140 Steel

Get Expert Help Today

Don’t risk picking the wrong steel for your next project! At Istar Machining, we specialize in helping you choose the right materials for your CNC parts machining.

Contact us today to discuss your next project. We’ll help you decide between 1018 and 4140 steel based on your exact needs, budget, and timeline.

Remember: The right steel choice saves money, time, and prevents part failures. Let our experts guide you to the perfect solution for your manufacturing needs.