UHMWPE Fiber (Dyneema/Spectra) SK99
Grade
also Dyneema, Spectra
SK99 = dyneema SK99
Top of the SK line — pick for weight-critical ropes, sailcloth and high-performance ballistic UD.
Values for the SK99 condition
Other UHMWPE Fiber (Dyneema/Spectra) grades and fills
UHMWPE Fiber (Dyneema/Spectra) is listed in 12 conditions; see the grade overview at UHMWPE Fiber (Dyneema/Spectra).
Compare all 12 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
UD cross-ply laminate | 0/90 cross-plied fiber in a low-modulus elastomeric matrix, consolidated into ballistic panels or hard-armor plates. | — | 1,300 | 3 | 62 Shore D |
Cut-resistant composite yarn | UHMWPE spun around glass or fine steel filaments for EN 388 level D–F cut-resistant gloves and sleeves. | — | 2,000 | 3.5 | — |
Honeywell general-purpose gel-spun grade | Honeywell's entry grade, equivalent class to SK60, for cordage, nets and cut protection. | — | 2,600 | 3.6 | — |
Dyneema SK60 | Lower-cost, lower-modulus grade for general cordage, cut-resistant yarns and non-critical composites. | — | 2,700 | 3.5 | — |
Chinese domestic high-strength UHMWPE filament | Pick the cost-driven SK65/SK75-class filament for ropes, nets and commodity armour at 3000 MPa and 100 GPa, accepting wider property scatter than branded yarn. | — | 3,000 | 3.5 | — |
high-tenacity armor/rope grade | Mid-tier Honeywell grade broadly comparable to SK75; used in Spectra Shield armor and high-strength lines. | — | 3,200 | 2.9 | — |
SK75Default Dyneema SK75 | Default workhorse gel-spun grade: best balance of tenacity, modulus and price for ropes, nets and soft armor. | — | 3,400 | 3.8 | — |
Dyneema DM20 | Fiber tuned for energy absorption in pressed hard-armor plates rather than for maximum static tenacity. | — | 3,400 | 3.8 | — |
highest performance Honeywell grade | Choose when maximum specific strength/stiffness is needed in Spectra-based armor or ultralight lines. | — | 3,400 | 2.9 | — |
Dyneema SK78 | Same tenacity class as SK75 but markedly lower creep — choose for permanently loaded mooring, rigging and lifting slings. | — | 3,500 | 3.8 | — |
Dyneema SK90 | Step up from SK78 for lighter, stiffer ropes and lines where minimum elongation matters. | — | 3,700 | 3.5 | — |
SK99This page Dyneema SK99 | Top of the SK line — pick for weight-critical ropes, sailcloth and high-performance ballistic UD. | — | 3,900 | 3.2 | — |
What is UHMWPE Fiber (Dyneema/Spectra) SK99?
UHMWPE Fiber (Dyneema/Spectra) SK99 is UHMWPE Fiber (Dyneema/Spectra) in the SK99 grade — top of the SK line — pick for weight-critical ropes, sailcloth and high-performance ballistic UD. UHMWPE Fiber (Dyneema/Spectra) SK99 has a tensile strength of 3,900 MPa (566 ksi), stronger than 90% of composite grades. Elongation at break is 3.2% and the elastic modulus is 140 GPa (20.3 Msi). UHMWPE Fiber (Dyneema/Spectra) SK99 has a density of 0.98 g/cm³ (0.0352 lb/in³), lighter than 82% of composite grades. Its glass-transition temperature is -120°C (-184 °F). SK75 is the default condition FabDigit quotes; SK99 is available on request or by drawing note.
Advantages
- Low moisture uptake — 0.01%, better than 99% of composite grades
- Good corrosion resistance — 92/100, better than 94% of composite grades
- Lightweight — 0.98 g/cm³ (0.0352 lb/in³), better than 82% of composite grades
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 80% of composite grades
- Ductile — tolerates forming and impact — 3.2%, better than 78% of composite grades
Limitations
- Limited service temperature — 70°C (158 °F), worse than 98% of composite grades
UHMWPE Fiber (Dyneema/Spectra) SK99 properties
Typical room-temperature values for UHMWPE Fiber (Dyneema/Spectra) SK99; 13 are specific to this condition. Other listed values are UHMWPE Fiber (Dyneema/Spectra) reference data and may not represent this condition. Bars are the position among composite grades.
Physical5
UHMWPE Fiber (Dyneema/Spectra) SK99 has a density of 0.98 g/cm³ (0.0352 lb/in³), lighter than 82% of composite grades. Its glass-transition temperature is -120°C (-184 °F).
Mechanical8
UHMWPE Fiber (Dyneema/Spectra) SK99 has a tensile strength of 3,900 MPa (566 ksi), stronger than 90% of composite grades. Elongation at break is 3.2% and the elastic modulus is 140 GPa (20.3 Msi).
Thermal7
UHMWPE Fiber (Dyneema/Spectra) SK99 is rated for continuous service to 70°C (158 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), better than 80% of composite grades.
Electrical4
UHMWPE Fiber (Dyneema/Spectra) SK99 has an electrical resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 94% of composite grades. UV resistance is good.
Sustainability3
Producing a kilogram of UHMWPE Fiber (Dyneema/Spectra) SK99 takes about 115 MJ of energy and emits 6.5 kg of CO₂ — less than 57% of composite grades. Typical recycled content is 0%.
Manufacturability1
UHMWPE Fiber (Dyneema/Spectra) SK99's machinability is poor (22/100, worse than 73% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with UHMWPE Fiber (Dyneema/Spectra) SK99
Is UHMWPE Fiber (Dyneema/Spectra) easy to machine?
Do not conventional-machine: cut yarn and fabric with hot knife, ultrasonic blade or laser; drilling laminates causes fuzzing and delamination — use sharp brad point at low feed.
Can UHMWPE Fiber (Dyneema/Spectra) be welded?
Fibers cannot be melt-welded without destroying orientation; laminates are joined by adhesive-free hot pressing of the UD matrix (~120–130 °C, 15–20 MPa) or mechanically fastened.
Can UHMWPE Fiber (Dyneema/Spectra) be formed, bent or molded?
Panels are consolidated in a heated press below 145 °C; no autoclave epoxy cure above ~130 °C, and any pre-tension must account for room-temperature creep.
What surface finishes work on UHMWPE Fiber (Dyneema/Spectra)?
Surface is chemically inert and very low energy — corona, plasma or chromic-acid etch is needed before printing, coating or bonding; pigmented (black/coyote) yarns are used for UV and camouflage.
UHMWPE Fiber (Dyneema/Spectra) chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| spin finish / surface treatmentresidual processing oil and finish on yarn surface | 0.2 – 1.5 | 0.7 |
| ethylene (–CH2–CH2–) repeat unit, Mw 3–6linear UHMWPE homopolymer; crystallinity 75–85 %, no comonomer | balance | — |
UHMWPE Fiber (Dyneema/Spectra) SK99 — frequently asked
What is UHMWPE Fiber (Dyneema/Spectra) SK99 used for?
UHMWPE Fiber (Dyneema/Spectra) SK99 is typically used for ballistic vests/helmets, high-strength ropes and rigging, cut-resistant gloves and lightweight composite panels. In short: highest strength-to-weight fiber; floats in water; limited to 70 C.
What is the tensile strength of UHMWPE Fiber (Dyneema/Spectra) SK99?
UHMWPE Fiber (Dyneema/Spectra) SK99 has a typical tensile strength of 3,900 MPa (566 ksi) — stronger than 90% of composite grades. Strength varies by condition: see the 12 listed tempers.
Is UHMWPE Fiber (Dyneema/Spectra) SK99 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 73% of composite grades). Do not conventional-machine: cut yarn and fabric with hot knife, ultrasonic blade or laser; drilling laminates causes fuzzing and delamination — use sharp brad point at low feed.
Can UHMWPE Fiber (Dyneema/Spectra) SK99 be welded?
Fibers cannot be melt-welded without destroying orientation; laminates are joined by adhesive-free hot pressing of the UD matrix (~120–130 °C, 15–20 MPa) or mechanically fastened.
What surface finishes work on UHMWPE Fiber (Dyneema/Spectra) SK99?
Surface is chemically inert and very low energy — corona, plasma or chromic-acid etch is needed before printing, coating or bonding; pigmented (black/coyote) yarns are used for UV and camouflage.
Can UHMWPE Fiber (Dyneema/Spectra) SK99 be formed, bent or molded?
Panels are consolidated in a heated press below 145 °C; no autoclave epoxy cure above ~130 °C, and any pre-tension must account for room-temperature creep.
What is the maximum service temperature of UHMWPE Fiber (Dyneema/Spectra) SK99?
UHMWPE Fiber (Dyneema/Spectra) SK99 is rated for continuous use to about 70°C (158 °F), and briefly to 130°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Dyneema SK60/SK75/SK78/SK90/SK99 and HB laminate fiber data sheets — DSM / Avient Protective Materials (2023)
- Spectra 900 / 1000 / 2000 fiber and Spectra Shield product data — Honeywell Advanced Fibers & Composites (2022)
- ASTM D2256 — Tensile Properties of Yarns by the Single-Strand Method — ASTM International (2021)
- Handbook of Properties of Textile and Technical Fibres — high-performance polyolefin fibres chapter — Woodhead / Elsevier (2018)
- ASM Engineered Materials Handbook Vol. 1–2 (Engineering Plastics / Composites) — ASM International (1988)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.