4" 10TPI T-Shank Wood High Carbon Steel Jig Saw Blades 5PK

What it is:

The 48-42-5540 is a Milwaukee 2-3/4" 14 TPI high-speed steel (HSS) jig saw blade set (5-pack) designed for heavy-duty metal cutting.

Key specs:

• Blade length: 2-3/4 inches
• TPI: 14 (coarse metal cutting)
• Material: High-speed steel (HSS)
• Shank: U-shank (standard universal fit)
• Pack size: 5 blades
• Best for: Thick metal (typically over 1/4")

Key features:

• 14 TPI aggressive tooth pattern: Fast cutting in heavy material
• HSS construction: Good heat resistance for sustained metal cutting
• Durable cutting edge: Designed for tougher jobsite use
• Fast material removal: Prioritizes speed over fine finish
• U-shank fit: Works with older and compatible jig saws

In plain terms:

This is a heavy-duty metal-cutting blade, similar in “role” to your 48-42-5190—but in an older U-shank + HSS format instead of newer T-shank bi-metal.

Best for:

• thick steel
• heavy-gauge sheet metal
• conduit and pipe
• fabrication work where speed matters

Where it fits in your blade system:

• 24 TPI blades (like 5161): thin metal / clean finish
• 18 TPI blades (like 5121): medium metal / balanced cuts
• 14 TPI blades (5540 this): thick metal / fastest aggressive cutting

So this is firmly in the “cut fast, don’t worry about finish” category.