• 📚 Yield Strength
    Rp and Rp0.2

  • 💪 How strong is the Titan?

  • 😱 Nightmare
    house fire

  • 🔬Corrosion resistance

Stress-strain diagram with Hookean region and representation of zones: Elastic Deformation, Plastic Deformation, Necking, and Fracture


Knowledge: The Yield Strength Rp

The Stress-Strain-Diagram shows the strain (ε) of the material on the x-axis, while the y-axis represents the stress (σ) applied to the material.

The value Rp is also known as the Yield Strength. Rp is defined as the point at which plastic deformation begins. Thus, Rp indicates the stress (= force per area) required to produce permanent deformation in the material.

Rp is an indicator of the material's ability to withstand stress without permanent deformation. A higher Rp value means that the material is more resistant to deformation and has greater strength.

Permanent deformation would destroy the Steel Wallet.

Stress-strain diagram with an explanation of the yield strength Rp0.2

Stress-Strain-Diagram - simplified

Rp0.2 = central material characteristic

Rp0.2 is a standard value in materials science and is available for (almost) every material.

When determining Rp0.2, the stress is measured at a specific point on the stress-strain curve, precisely at a plastic deformation (=strain) of 0.2%.

Rp0.2 is ultimately easier to determine than Rp, which is why the latter is used as a reference value in science.
Material illustration of the Titan Wallet - AISI316TI for Base Body and Seed Discs, Titanium Grade 5 for the inner, AISI 316 for the Caps.

Bitcoin meets German Engineering

Structure & Material

The two-part design (outer and inner housing) and the choice of materials are designed for the safety of your seed.

The base body and seed discs are made of AISI 316Ti (Titanium Alloy Stainless Steel, 1.4571) for optimal protection.

The inner housing is 100% titanium grade 5 (3.7165). It serves as a second, extremely strong protective shield for your seed.
to the store
Comparison Yield strength Steel Wallets Titanium Grade 5, Titanium Grade 2, AISI 316Ti, 316, 304

Comparison of Rp0.2 of various materials

Quality instead of Marketing

With other steel wallets and backup solutions, you regularly read woolly marketing slogans like "finest stainless steel" or "high-quality titanium". The actual material used is usually well hidden or not even mentioned.
Sad but true, the "finest stainless steel" is often just a standard AISI 304 (1.4301) stainless steel. Titanium is usually Grade 2 (3.7035). With titanium, the choice of this weaker variant is obvious, since you would have to use more than 4 times the force to hammer your seed into titanium Grade 5 (compared to the stainless steels AISI 304, 316 or 316Ti). At most, Roman Reher can manage that...
Yield Strength of stainless steel with increasing temperature: AISI 316Ti > AISI 316 > AISI 304

Stainless steel: 316Ti is the clear favorite

316Ti stainless steel has been specially developed to maintain high strength at high temperatures. The titanium carbides in this stainless steel make it possible.

Unfortunately, the vast majority of steel wallets and backup solutions are made of 304 stainless steel....
Yield strength of titanium with increasing temperature: Titanium Grade 5 > Titanium Grade 2

Titanium Grade 5 is undisputed

A graphic says more than 1000 words. Thanks to additives (=alloys) such as alumiunium and vanadium, this material has excellent properties.
Since Titanium Grade 2 is much cheaper, this material is often used. But not in our case!

Fun Fact: Titanium Grade 5 was originally developed for aerospace applications. 🚀
Corrosion resistance: AISI 304 (good), 316 (very good), 316Ti (very good), and Titanium Grade 2 (excellent) and Titanium Grade 5 (excellent)

Resistance to corrosion and acid

Titan Wallet: Very Good to Excellent!

Titanium has excellent resistance to corrosion and acids and is one of the few materials considered resistant to seawater.

AISI 304 is largely adequate for normal use. 304 is sensitive to chlorides and acids and is also somewhat susceptible in saline media.

Steels 316 and 316Ti are less sensitive in this respect. For example, they are even resistant to sulfuric acid (1%).

PREN = Pitting Resistance Equivalent Number

Disclaimer: Most values shown are approximate values
(which can be traced in the corresponding standard and/or in the following sources).

Do your own research!

The information on this page is mainly derived from the following sources

Bargel, H.-J. (Hrsg.) 2022 - Werkstoffkunde

Wittel, Spura et al. 2021 - Roloff/Matek Maschinenelemente

Deutsche Edelstahlwerke (https://www.dew-stahl.com/)

Zapp AG (https://www.zapp.com/)

TEAM EDELSTAHL GmbH & Co. KG (https://www.teamedelstahl.de/)

Walter Kaiser Gmbh (https://www.beizgmbh.de/documents/Edelstahlvertraeglichkeit.pdf)