Seaguar JDM Grand Max Leader
Leader diameter chart & setup guide
Grand Max is a leader and tippet material in Seaguar's US JDM collection. It uses two fluorocarbon resins and comes on thin, connectable 60-meter spools. Strengths such as 17, 19, 24 and 27 lb are the actual labels, so choose the size printed on your spool.
- Construction
- 100% fluorocarbon; Seaguar double-structure process
- Listed strengths
- 2-40 lb
- Role
- Terminal leader
Is JDM Grand Max Leader right for your setup?
Grand Max suits a terminal leader or tippet choice when its exact diameter and knot behavior meet your rig requirements. Its thin, connectable spools organize a range of sizes without treating each package as a reel fill. Compare the metric diameter as well as the US pound label before choosing the next size.
Choose your Seaguar JDM Grand Max Leader
A package supplies multiple leaders
The package length is the amount you buy, not the leader length to attach to one rig. Allow extra line for knots, tag ends, trimming, and replacing damaged sections.
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Seaguar JDM Grand Max Leader diameter chart
US-import JDM collection, exact xxGM66 product codes. Published inch/mm pairs preserved within their display precision; package is 60m, with yards converted.
| Strength | Inches | mm | Package length |
|---|---|---|---|
| 0.004 | 0.104 | 60 m (about 65.62 yd) | |
| 0.005 | 0.128 | 60 m (about 65.62 yd) | |
| 0.006 | 0.148 | 60 m (about 65.62 yd) | |
| 0.007 | 0.165 | 60 m (about 65.62 yd) | |
| 0.007 | 0.185 | 60 m (about 65.62 yd) | |
| 0.008 | 0.205 | 60 m (about 65.62 yd) | |
| 0.009 | 0.22 | 60 m (about 65.62 yd) | |
| 0.009 | 0.235 | 60 m (about 65.62 yd) | |
| 0.01 | 0.26 | 60 m (about 65.62 yd) | |
| 0.011 | 0.285 | 60 m (about 65.62 yd) | |
| 0.012 | 0.31 | 60 m (about 65.62 yd) | |
| 0.013 | 0.33 | 60 m (about 65.62 yd) | |
| 0.015 | 0.37 | 60 m (about 65.62 yd) | |
| 0.016 | 0.405 | 60 m (about 65.62 yd) | |
| 0.017 | 0.435 | 60 m (about 65.62 yd) | |
| 0.019 | 0.47 | 60 m (about 65.62 yd) | |
| 0.02 | 0.52 | 60 m (about 65.62 yd) |
Choosing and using JDM Grand Max Leader
Choose the leader for the terminal connection, cover, lure, and knot requirements. The leader's pound-test label does not determine how much braid fits on the reel.
The US 8 lb and 10 lb labels both round to .009 inch, but their published metric diameters are .220 and .235 mm. Keep that difference visible when selecting leader size.
UK Grand Max tippet uses different strength labels and package lengths. Do not merge it with this US-import JDM collection.
Specification-based leader guidance, not a hands-on JDM Grand Max Leader test. Select terminal material independently of the reel's mainline capacity.
Treat 60 meters as leader supply
Choose an individual leader length for your rig, allowing material for knots and replacement. Do not use the whole 60-meter package as a default leader or as a mainline fill recommendation.
Keep nearby labels distinct
Label each spool by the actual test and diameter. The 17, 19, 24 and 27 lb options are not interchangeable with conventional 15, 20, 25 or 30 lb labels.
Protect the remaining material
Keep the free end controlled on the compact spool and separate damaged material from the unused supply. Check the terminal section and connection after abrasion or a hard pull.
Plan the line on your reel separately
A short terminal leader is not the working line that fills your spool. Use the actual main line in the calculator or Setup Wizard. A long topshot that occupies substantial spool space needs its own capacity plan.
JDM Grand Max Leader questions, answered
Should Grand Max fill the reel?
This product is documented as leader/tippet material. Calculate the working spool with the actual main line, then select Grand Max for the terminal section.
Can 19 lb be renamed 20 lb?
No. 19 lb is the exact published US variant label, product code 19GM66. A nearby familiar pound test is a different identity.
Is 66 yards a second package?
No. Seaguar describes one 60-meter package and rounds that amount to 66 yards. The exact metric conversion shown here is approximately 65.62 yards.
Specifications & sources
Checked 2026-09-13 against Seaguar US JDM product and exact assigned variant/product code response. Published inch/mm pairs retained. The stated 60-meter spool is converted to 65.62 yards; the source rounds it to 66 yards. Separate from UK Grand Max. The manufacturer illustration combines representative items; use the assigned variant table for each exact diameter, not both pictured labels as one product code.
- Seaguar official product evidence 1 Exact model identity and manufacturer specifications; reviewed 2026-09-13.
- Seaguar official product evidence 2 Supporting specification, package or chart evidence; see source note for scope.