ASTM F468 UNS R58640 represents grade specification for Titanium Grade 19 Bolts, Screw Fasteners. It covers both coarse and fine threaded Ti Alloy 19 Bolts, screws, stud bolts. Below is the chemical, mechanical and other requirements. ASTM F468 UNS R58640 Fasteners carry EN 10204 Type 3.1 Certification.
| Composition, % Titanium and Titanium Base AlloysA |
|||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UNS Designation | Alloy | General Name | Aluminum | Carbon | Iron | Titanium | Hydrogen | Nitrogen | Oxygen | Palladium | Vanadium | Chromium | Molybdenum | Zirconium | Tin | Silicon | ResidualsB | ||
| Each | Total | ||||||||||||||||||
| R58640 | 19 | Titanium Ti-28-6-44 | 3.00 - 4.00 | 0.05 | 0.30 | balance | 0.0200 | 0.03 | 0.12 | 0.10D | 7.50 - 8.50 | 5.50 - 6.50 | 3.50 - 4.50 | 3.50 - 4.50 | -- | -- | 0.10D | 0.15 | 0.40 |
A All reported values are maximums, unless a range is specified.
B A residual is an element present in a metal or an alloy in small quantities inherent to the manufacturing process but not added intentionally. Residual elements need not be reported unless a report is specially required by the purchaser.
C Identical chemical requirements apply to both Class A and B as defined in Table 2 and 6.5 of ASTM F468.
D Ruthenium and palladium, or both, may be added to Grade 19 for enhanced corrosion resistance as negotiated between purchaser and vendor. Chemical analysis is not required unless specifically required by the purchaser.
| Alloy | Mechanical Property Marking | Nominal Thread Diameter, inch | HardnessA | Full Size Tests B | Machined Specimen Tests | |||
|---|---|---|---|---|---|---|---|---|
| Tensile Strength, min, ksi | Yield Strength, min, ksiC | Tensile Strength, min, ksi | Yield Strength, min, ksiC | Elongation in 4D, min %D | ||||
| Titanium Alloys | ||||||||
| Ti 19 | F 468FT | all | 24 - 38 HRC | 115 - 150 | 115 | 120 | 115 | 15 |
A where both tension and hardness tests are performed, the tension tests shall take precedence for acceptance purposes. For alumium and titanium alloys, hardness tests are for information only.
B The yield tensile strength values for full size products shall be computed by dividing the yield and maximum tensile load by the stress area for the product diameter and thread pitch as given in table on tensile stress areads.
C Yield strength is the stress at which an offset of 0.2% gauge length occurs.
D Elongation is determined using a gauge length of 4 diameters of test specimen in accordance with Test Methods E8.
E "HF" denoted a hot formed product
F Aluminum alloy temper designations are in accordance with ANSI H35.1.
G Full size test mechanical properties apply to fasteners with a maximum diameter of 76 mm. Mechanical properties of larger sections shall be negotiated between the material manufacturer and the fastener producer.
H Ti 5 Class A requires wedge test tensile testing in accordance with section 6.6 & Ti 5.5 Class B requires wedge tensile testing in accordance with section 6.5.1 of ASTM F468.
| Nominal Size, inch. | Coarse Threads - UNC | Fine Threads - UNF | 8 Thread Series - 8UN | |||
|---|---|---|---|---|---|---|
| Threads / inch | Stress AreaA, in2 | Threads / inch | Stress AreaA, in2 | Threads / inch | Stress AreaA, in2 | |
| 1/4 | 20 | 0.0318 | 28 | 0.0364 | -- | -- |
| 5/16 | 18 | 0.0524 | 24 | 0.0580 | -- | -- |
| 3/18 | 16 | 0.0775 | 24 | 0.0878 | -- | -- |
| 7/16 | 14 | 0.1063 | 20 | 0.1187 | ||
| 1/2 | 13 | 0.1419 | 20 | 0.1599 | ||
| 9/16 | 12 | 0.1820 | 18 | 0.2030 | ||
| 5/8 | 11 | 0.2260 | 18 | 0.2560 | ||
| 3/4 | 10 | 0.3340 | 16 | 0.3730 | ||
| 7/8 | 9 | 0.4620 | 14 | 0.5090 | ||
| 1 | 8 | 0.6060 | 12 | 0.6630 | ||
| 1 1/8 | 7 | 0.7630 | 12 | 0.8560 | 8 | 0.790 |
| 1 1/4 | 7 | 0.9690 | 12 | 1.0730 | 8 | 1.000 |
| 1 3/8 | 6 | 1.1550 | 12 | 1.3150 | 8 | 1.233 |
| 1 1/2 | 6 | 1.4050 | 12 | 1.5810 | 8 | 1.492 |
A Tensile stress areas are computed using the following formula: As = 0.7854 [D- (0.9743/n)]2
Where:
As = Tensile stress area, in.2,
D = Nominal size (basic major diameter), in., and,
n = number of threads per inch.
| Alloy | Test Method |
| Titanium | E120, E1409 |