NLGI Grades Explained: Grease Consistency Guide

What is NLGI Grade?

The National Lubricating Grease Institute (NLGI) grade is a standardized measure of grease consistency, ranging from 000 (very soft, fluid-like) to 6 (very firm, block-like). NLGI 2 is the most common grade for industrial bearing applications, offering a balance of pumpability and staying power.

NLGI Grade Chart

NLGI Worked Penetration (0.1mm) Consistency Typical Application
000 445-475 Very soft / fluid Enclosed gearboxes, centralized systems
00 400-430 Semi-fluid Centralized lubrication, gearboxes
0 355-385 Very soft Centralized systems, low-temp applications
1 310-340 Soft Low-temperature bearings, high-speed applications
2 265-295 Medium / buttery Standard industrial bearings (most common)
3 220-250 Firm Large bearings, vertical shaft applications
4-6 <205 Very firm / block Block grease, large open gears

FAQ

Q: How do I choose the right NLGI grade?

Selection depends on bearing size, speed, temperature, and application method. NLGI 2 is the default for most industrial bearings. NLGI 1 provides better low-temperature pumpability. NLGI 3 resists slumping in vertical shafts. Always consult your equipment manufacturer's specification.

Q: Can I use NLGI 1 instead of NLGI 2?

In many cases, yes ā€” especially in cold environments where NLGI 1 offers better pumpability. However, NLGI 1 may leak from bearings designed for NLGI 2. The softer consistency provides less sealing capability but better flow at low temperatures.

Q: Why does grease consistency matter?

Consistency affects pumpability in centralized systems, retention in bearings, sealing against contaminants, and low-temperature starting torque. Too soft ā€” grease leaks out. Too firm ā€” grease doesn't reach the lubrication point.

Q: How is NLGI measured?

NLGI grade is determined by the worked penetration test (ASTM D217). A standard cone is dropped into a worked grease sample, and the penetration depth in tenths of a millimeter determines the NLGI number.

Q: How does temperature affect NLGI?

Grease softens as temperature increases and hardens as temperature decreases. A grease rated NLGI 2 at room temperature may behave like NLGI 1 at 80Ā°C or NLGI 3 at -20Ā°C. This is why temperature range is a critical selection factor.

KOEED Support

Need help selecting the right grease for your application? Contact KOEED at Moritta@KOEED.COM. Our technical team can provide KLƜBER product recommendations based on your operating conditions.

Related Articles

Torna al blog

Blog posts

  • ABB MJS6-60B + 4Ɨ MCB-10 Power Distribution Kit...

    Explore the ABB MJS6-60B main isolation switch paired with four MCB-10 miniature circuit breakers ā€” a pre-engineered 2026-ready power distribution kit that accelerates panel builds, ensures IEC 61439-2 compliance, and...

    ABB MJS6-60B + 4Ɨ MCB-10 Power Distribution Kit...

    Explore the ABB MJS6-60B main isolation switch paired with four MCB-10 miniature circuit breakers ā€” a pre-engineered 2026-ready power distribution kit that accelerates panel builds, ensures IEC 61439-2 compliance, and...

  • ABB MJS6-60B Modular Joystick: The 2026 Bluepri...

    Discover why the ABB MJS6-60B 4-position momentary joystick is the definitive HMI component for 2026's smart factories. This comprehensive engineering guide covers IP69K-rated durability, ROI analysis, predictive maintenance integration, and...

    ABB MJS6-60B Modular Joystick: The 2026 Bluepri...

    Discover why the ABB MJS6-60B 4-position momentary joystick is the definitive HMI component for 2026's smart factories. This comprehensive engineering guide covers IP69K-rated durability, ROI analysis, predictive maintenance integration, and...

  • MJ-150-A Advanced PLC Module: 2026 Guide to IT/...

    Discover the MJ-150-A PLC module ā€” a 2026-ready industrial automation component engineered for seamless IT/OT convergence, energy-efficient operations, and predictive maintenance. This comprehensive B2B technical guide covers specifications, benchmarking, ROI...

    MJ-150-A Advanced PLC Module: 2026 Guide to IT/...

    Discover the MJ-150-A PLC module ā€” a 2026-ready industrial automation component engineered for seamless IT/OT convergence, energy-efficient operations, and predictive maintenance. This comprehensive B2B technical guide covers specifications, benchmarking, ROI...

1 3