Pipe Material e (mm) e (ft) Glass, drawn brass, copper (new) 0. 78 Pipe Entrance Flush Sharp-Edged 0. 6 – 0. com Get a Quote: [email protected] = 0. (10-6 in/ (in oF)) Admiralty Brass. become more important for the design of cold-formed stainless steel structural members. They are classified into martensitic, austenitic, and ferritic steels based on their crystalline structure. Deflector. Defining the Neutral Axis To understand the k-factor,. 36 N in air, wear surfaces are covered by oxide films and fine and thin wear particles of 0. . The K-factor is used to determine the length of the metal plate stretched during the bending process. 3 which will result in K factor of 0. h fThermal expansion of pipes and tubes - stainless steel, carbon steel, copper, plastics and more. ComponentDefinition kFac = oCompDef. S. Piping Material. 2 U. Hs = Static Suction Lift (m). To help you begin I’ve included a K-Factor Chart below which contains common K-Factor starting points, good for general fabrication, for steel, aluminum and stainless steel. Importance of the K-factor in sheet metal design. Super strong with added corrosion resistance. 1994, ISBN: 978-0-87170-503-7. Related Documents Bimetallic Strips Heat and bending of bimetallic strips. Where high strength is. ANTI-SEIZE Stainless does not contain copper and exhibits extremely low sulphur and chlorine. *C 1 AN219207 Inductive Sensing Design Guide Authors: Paul Walsh, Dineshbabu Mani Associated Part Family: PSoC® 4700 Software Version: PSoC Creator™ 4. Connection Type. We multiply this factor by the material thickness to determine the distance the neutral axis shifted toward the inside radius during bending. 6. Churchill Friction Factor Formulae and. Bend Allowance (BA) =. Zinc Plated Steel. Steel: 90: 110 – Galvanized iron: 120: 120: Polyethylene: 140: 140: Polyvinyl chloride (PVC) 150: 150: Fibre-reinforced plastic (FRP) 150: 150:Sheet Metal Gauge Chart. You just have to insert the characteristics of the sheet metal to be bent. 446. However, the washer is normally flat by. So what is the perfect K Factor for the Mild Steel and Stainless Steel? The “K” factor variation ranging from 0. 6. Another way to calculate this value is with the K-factor or Y-factor. The TYCO Series TY-FRB, 5. 3 in. Response. NIKAL contains no graphite, which is a benefit on stainless steel applications when temperatures exceed 550°F, as graphite can carburize the steel causing the steel to become much more susceptible to intergranular corrosion. Stainless Steel 316 . For horsepower at the motor (HPm), use formula: HPm = HPC/E. Overall heat transfer coefficient is expressed as W/m2 °C or kcal/h, m2 °C. 3 depending on the raw material. The four types stainless steels used in this study were SUS410 (t = 3. Portuguese / português. Standard Metric; S-256-X: 2-56. 33 K factor 0. 33: K factor:. The friction coefficient value changes not only with material but also with the position and. The K-factor is used to calculate flat patterns because it is related to how much material is stretched during bending. Steel Hex Locknut Steel Hex Flange Nut Grade C FNL Grade 9 Grade F Grade G Clamp Load (lbs. Step 1: Choose Meter Type. Step-3: Value of Bend Deduction and Flat pattern are shown in Result Section. The alloy resists oxidation to 1500°F (816°C) and has higher creep and stress rupture properties than alloys 304 and 304L. Stainless steel (SS), nickel foil (Ni), titanium foil (Ti) and graphite plate (GP). 16. r = relative roughness. 33 K factor 0. 64 x 19. 4. 01 (m) and Reynolds number Re = 10 7 - the relative rougness can be calculated as. units by 10. Food grade anti-seize compounds are manufactured from white oil and include extreme pressure (EP) additives. AISI 316 Stainless Steel (UNS S31600) AISI 316 stainless steel (UNS S31600) is the second most commonly used austenitic stainless steel. 77 Material Iron metal Steel Steel r. Our free online sheet metal bending calculator enables you to rapidly determine the crucial parameters in sheet metal bending calculations, such as the K-factor, Y-factor, bend allowance, bend deduction, arc length, and unfolding flat size. Bulletin 038. Modeling up my first stainless steel parts, as I usually only use mild steel. 0015 10 -3 m) / (0. 20 Ecoguard K = 0. less steel types are designated by the American Iron and Steel Institute as standard compositions. A black body is a material that is a perfect emitter of heat energy and has an emissivity value of 1. 5 max) serves as a control figure in sheet metal bending calculation. e. 000013 : Commercial steel (enamel coated) We are going to review three bending scenarios with three different bending angles; 60, 90 and 120, and we will calculate K-Factor, Bend Allowance and Bend Deduction for them. Bend allowance chart for SUS (stainless steel) 3. You could be the first review for Silver Fern. Riveted steel (new) 0. This formula considers the diverse geometries and properties of the parts to be formed. 33 K factor 0. 2 ext { m}^2 A= 1. Notes：. Very often what people use is some general data that may or may not be close enough. The Y-Factor is used, as far as I know, solely by PTC’s Pro-Engineer, now known as Creo Elements/Pro. •G is the geometry factor •qis the thermal conductivity integral. The bend deduction, sometimes called the bend compensation, describes how much the outside of the sheet has been stretched. The tensile, fracture, and fatigue crack growth properties of 316L stainless steel (SS) produced using the selective laser melting (SLM) technique were evaluated and compared with those of conventionally manufactured (CM) austenitic SSs. 81 m/s 2] The value of the friction factor is dependent on the Reynolds number, the shape of the pipe, and the roughness of the pipe walls. Requirement is based on minimum flow in GPM from each sprinkler. 17 8. 10 0. The k-factor can be calculated from the bend allowance. To enhance its properties, alloying elements can be added to steel. The thermal conductivity coefficient k is a material parameter depending on temperature, physical properties of the material, water content, and the pressure on the material [3]. Microform Precision, LLC 4244 South Market Court, Suite A Sacramento, CA 95834 Phone: (916) 419-0580 Fax: (916) 419-0577 Email: [email protected] A36 Steel 3/8” less than 50 53. The K-factor is simply the tangent of half the bend angle. L = Length of the coil or pipe. The below Excel chart is for even-numbered material gauges 8 through 22 and has a default K-Factor of . Copper and brass: 0–0. 5–1°. In our case, we will use the table for ALUMINUM-INCH. Sheet metal thickness is denoted by gauge, sometimes spelled gage, which indicates a standard thickness before processing. In the process of making stainless steel, alloying elements such as chromium (Cr), nickel (Ni), manganese (Mn), silicon. 67. The PVC pipe calculation are made with the Online Hazens-Williams Calculator with a roughness coefficient c = 145. Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness. Our Passivation and Pickling services include the following main processes: Stainless steel pickling, stainless steel passivation, and carbon steel pickling. Stainless steel 430 - 1. The chemical compositions (in mass%) of these four types of stainless steels are shown in Table 1. Bend Radii And K Factors For 304 Stainless Steel. By definition, “stainless” steel must contain at least 10. For molded ceramic fiber products and packed or tightly packed insulation, losses will be lower than values shown. For high-strength, low-alloy, and stainless steels, 1,800 pounds of pressure per lineal inch should be used. Stainless Steel Pickling. These are 304 SS material. Sustainable building with Stainless steel - The David L. In general, a material with a large k is a good heat. Mechanical Properties Typical Values at 68°F (20°C) Yield Strength Ultimate Tensile Elongation Hardness 0. 1 mm and bend radius as 1 \text { mm} 1 mm. Sheet Metal Bending Calculator. ISBN: 978-0-87170-503-7. v = Velocity of the incompressible fluid. R. 88CO 2 eq. Bending aluminium is even more complex, since aluminium is less ductile than steel. Where the neutral axis is situated in a bend is commonly called the “K-Factor” as it is signified as “K” in the development formulas. 26 (304/316. 5mm up to 6. The K-factor is defined as the distribution of the component between the hydrate and the gas ( Carroll, 2014 ): (8. DIN 913 Flat Point; DIN 914 Cone Point; DIN 915 Dog Point; DIN 916 / ISO 4029 Cup Point; A2/A4 Stainless Steel; DIN 479-8. 17 found in seemingly identical fasteners here results in a substantial clamp load variation. K = K-Factor, which is t / T. 446 inch. For example: A spring is compressed 16 mm and the spring constant is 3 N (16 mm * 3 N = 48 N) A spring that travels 16 mm thus produces 48 N, which equates to approx. 5% is ideal. We bend lots of stainless, which in terms of hardness, is very similar to mild steel (a36/gr50/cq) If I were to start folding, I would use . Generally, when design the sheet metal parts, the min inner R=thickness/2, if less than that, the grooving (V-cutting) will be required to solve the. Table 2 - Mechanical properties of 301 grade stainless steel. Bend allowance with a K-Factor is calculated as follows: BA=pi (R + KT) A/180. The nozzle is available in brass, stainless steel 316 and aluminium bronze construction. Also, it does not account for the temperature or viscosity of the water. K-Factors for TX series flow meters are valid ONLY for meters purchased after January 1, 2011. The value of k is 0. Material. MC values range between 0. The friction loss in feet of head per 100 feet of Steel pipes Schedule 40, Copper pipes Type L and thermoplastic PVC pipes Schedule 40 are compared below. (K-factor). Joint Tightness 95 3. Editor: J. Although, measurement variations by an order of 10-1 have been observed, the. The effect of this minimum level creates a chromium oxide layer on the surface, which is a self-healing oxygen barrier that stops further oxidation. The higher price for stainless steel fasteners and stainless steel nuts comes from the process of making stainless. [Stainless steel 735 ] 25. The calculations referenced in Paragraph 304. k = roughness of duct, pipe or tube surface (m, ft) There is a direct relationship between sheet metal bend allowance and the K-factor. Hazen-Williams Coefficients Table. A typical value of the K factor varies between . 820 × 3. The k-factor is found by dividing time by the thickness of the material: The formula for the k-factor is t/Mt. It can be used in certain chemical applications due to its resistance to nitric acid. Prefix- (S)Steel - (CLS)Stainless Steel. Stainless Steel: Water: 120: 680: 1 Btu/ft 2 hr o F = 5. We want to know the final length of the detail. However, this steel can be cold. kFactor iProperties. Hot food in stainless steel containers. Stainless Steel Stainless steel is a family of iron-based alloys that must contain at least 10. Here are the steps to be followed to calculate sheet metal flat length: Step-1: Enter Flange Length, Internal Radius, and thickness values. 5×10 –6 /°F). r. In our case, we will use the table for ALUMINUM-INCH. The bend deduction, sometimes called the bend compensation, describes how much the outside of the sheet has been stretched. Features a 3/4 inch NPT (20 mm BSPT) thread size and 8. . K-Factor transformers are designed not to eliminate harmonics, but to withstand their negative effects. The inside radii are based off of a standard Air Bend Force Chart. Click here for a Gauge to mm Conversion Chart . The bending tool has a radius of 30 mm which means that our Inside Bend Radius (R) is 30 mm. When compensating for Spring Back in materials such as stainless steel Coining is typically not the best option unless you are working with thin gauges. 25 to 0. MIL-PRF-907F; Service. A hole should be at least three times material thickness away from the edge of the dimple. The reason being that it takes the wear rate, the applied load, and the hardness of the wear pin into account. It is defined as the fraction of energy being emitted relative to that emitted by a thermally black surface (a black body). Stainless steel 1kg = 6. The k-factor is just a multiplier that provides a precise estimate of the new position of the neutral axis. The lowest expansion is found in the iron-nickel alloys such as Invar. Carbon steel in a broader sense sometimes. Base part number is shown. It is the thermal resistance of unit area of a material. It has high strength and corrosion resistance. 0 ±5% 2. by：East King 2020-08-30. Next we simply need to choose the specified gauge of 10. Hazen-Williams Friction Factor (C) Pipe Material Values for C Range High/Low Average Value Typical Design Value Plastic, PVC, Polyethylene pipe or tubing 160/150 150-155 150 Cement or mastic lined iron or steel pipe 160/130 148 140 Copper, brass, lead, tin or glass pipe or tubing 150/120 140 130 Wood Stave 145/110 120 110Use of alloy 2507 super duplex stainless steel at temperatures above 482°F (250°C) causes microstructural changes that lead to embrittlement and loss of corrosion resistance. The tool can calculate the required bending force for bending aluminum, stainless steel, mild steel, and Weldox® or Strenx® high-strength steels. 4 Btu/ft·h·°F at 212 °F), yield. 0. K-factor= [Multiplier × (Inside Radius/Material Thickness)] + Minimum K-factor. For example, chromium can be added for corrosion resistance, nickel can improve toughness and ductility, and. 012". 33 K factor 0. Inside temperature in the exchanger is 100 o C and outside temperature is 20 o C . 75–1°. The bending tool has a radius of 30 mm which means that our Inside Bend Radius (R) is 30 mm. Circular Ring - Temperature Expansion Calculate ring (or pipe) diameter expansion or contraction when temperature changes. K-factor (aeronautics), the number of pulses expected for every one volumetric unit of fluid passing through a given flow meter. Stainless Steel 404. Show advanced filters Hide advanced filters. Additional Information: NOTICE: The product details indicated below are for general reference only and may vary based on the specific product approval and/or application. Roughness (mm) Drawn Tubing, Glass, Plastic. T = material thickness. 64-Rubber (60 A Belt). Mathematically bend allowance during Sheet metal bending can be calculated as per the following formula. Is it used in a variety of industries due to its combination of strength and corrosion resistance versus cost. Step 1a: Choose Installation Type. 0 K-factor Stain - less Steel Pendent Sprinkler cannot be installed in a recess pendent arrangement. Most of our threaded connections use thread inserts of some kind, mostly helicoil, or PEM. 0 Nominal K Factor S. 079 0. Stainless Steel 330 (X12NiCrSi36-16):Cutting conditions, Recommended Carbide Grades, Equivalent Material Standards, and Chemical Composition. T – material thickness in m. 4(28) for iron pipe or equivalent rigid pipe, in Table 402. Neutral Axis Representation. 33: K factor:. 0 (11. So we bend a lot of mild steel. To work the following formula, you need to convert the inside bend radius and material thickness measurements from inches to millimeters. The “K” factor is a power constant that represents the number of cubic inches of metal per minute that can be removed by one horsepower. Other applications include fasteners and screens for the mining industry. While the sheet metal’s inner surface contracts, the exterior expands. At room temperature, it has the tendency to become brittle, especially when it has been heated for a long time in the 400-600°C (752-1112°F) range. Hazard. For exact calculations - always check manufacturing data. Stainless steel is the general name for a family of steels that are corrosion-resistant and contain a minimum of 10. An air to air plate exchanger with area 2 m 2 and wall thickness 0. The only study available in the literature for the SCFs of SST joints is by Feng and Young [9], who examined the SCFs of stainless steel SHS and rectangular hollow section (RHS) tubular X-joints. Next we use the pull-down menu to select the appropriate table. It has excellent resistance to intergranular corrosion after exposure to temperatures in the chromium carbide precipitation range of 800–1500°F (427– 816°C). The best single-volume reference on the metallurgy, selection, processing, performance, and evaluation of stainless steels, incorporating essential information culled from across the ASM Handbook series. Style: Upright. F f = μ N (1). For plate under 2mm, K-factor is 0. PENDENT APPROVALS/LISTINGS SIN V2801 V4201 V2708 V3406 Nominal K Factor Imperial 2. For a PVC pipe with absolute roughness k = 0. Davis. The maximum temperature increase relative to the environment inside the enclosure can be determined from the following equation: (Ti-Tu) = Qv / (k*A) Where:The results demonstrate that, generally, Nitinol K wires have a shorter life for the same applied stress than the stainless steel or titanium wires. Mechanical Engineer. Copper, Ductile Iron, Carbon Steel, Stainless Steel and Aluminum Piping Materials - Temperature Expansion Thermal expansion of typical piping materials. 6 (80), 8. 6 8-32 Stainless Steel Fasteners Material Length of Thread Engagement (in) Experimental Torque Applied (in-lb) Calculated Torque From Tables (in-lb) 304 Stainless Steel 7/16” between 57-60 77. 2 m2. stainless steel with good general corrosion resistance. For instance if you have a material with an R-value of 12 attached to. A com plete listing of all AISI stainless steels and a description of each are contained in the AISI publica tion, "Steel Products Manual -Stainless and Heat-Resisting Steels, December 197 4. 4 77. 237 in, thickness tolerance 12. 88. Therefore it is important to have the value correct in CAD software. ,. Part Number: 13500. Example - Linear Expansion. Includes additional data and reference information carefully selected and adapted. Continue to determine the radius of gyration r according to the cross-section of the column: r = √(I / A). For complete part number, refer to Viking’s current price schedule. In materials science, fracture toughness is the critical stress intensity factor of a sharp crack where propagation of the crack suddenly becomes rapid and unlimited. Fracture toughness. 1. 15-5 stainless steel is a martensitic, precipitation hardening steel designed for higher strength than 17-4 stainless. Multiply the volume with density to get the 12 mm steel weight:300 K vacuum vessels but care must be taken that breaks. DIN 913 Flat Point; DIN 914 Cone Point; DIN 915 Dog Point; DIN 916 / ISO 4029 Cup Point; A2/A4 Stainless Steel; DIN 479-8. 10. In most cases for built-up metal cladding, ∆U’’ = 0. Enter the area of contact, A = 1. Zheng, C. 8 Bare Steel with Guide Point; DIN 7984-8. This article discusses the properties and applications of stainless steel grade 304 (UNS S30400). Metric K-factor shown is for use when pressure is measured in bar. sliding (slip between surfaces) where μ s is the coefficient of static friction and μ k is the coefficient of kinetic friction. Italian / italiano. K-Factor is the ratio of the neutral axis to the material thickness. 4(30) for smooth wall semi-rigid tubing, in Table 402. The baseline material factor (1. Hust, J. table - i : material of construction table - ii : approval data k-factor spray angle model & approvals mv-a brass, without strainer mv-as brass, with strainer mv-b stainlessAISI Type 316 Stainless Steel, annealed sheet. This specification covers chromium, chromium-nickel, and chromium-manganese-nickel stainless steel plate, sheet, and strip for pressure vessels and for basic. The K-factor is the most popular way of calculating the bend allowance and bend deduction, but there are multiple ways that this calculation can be done. Cut a blank to a specific length (say 100mm) and measure it as accurately as possible. Horizontal Sidewall. It comes with option of several k-factors and spray angles and. For example, the UL Listing is based on the requirements of NFPA 13, and the FM Approval isYou can easily modify the Material Thickness, Inside Radius and K-Factor for each thickness at the top of each column. See More Items from this Family (3)We would like to show you a description here but the site won’t allow us. (Learn proper lubrication techniques in our Level 1 course — now available free. With this equation, if you know K, F and D, you can multiply them to get the torque needed to tighten the bolt so that it has the right amount of tension. 33 K factor 0. Material Iron metal Steel Stainless steel kg 6. 84. 7 333 8 in-lbs 10 in-lbs 858 18 in-lbs 20 in-lbs 27 in-lbs 1228 25 in-lbs 29 in-lbs 39 in-lbs 1436 29 in-lbs 34 in-lbs 45 in-lbs 5 0. where T is the torque measurement, K is the nut factor, F is the tension and D is the bolt diameter. 76 · 10 4 so that CR is in [mm/y], m loss is the mass loss [g] of the metal (m 0 − m f) in time t [hours], A is the surface area of the material exposed [cm 2], and ρ is the density of the material [g/cm 3] (ASTM, 2012; Kreysa & Schütze, Reference Kreysa and Schütze 2007; Kutz, Reference Kutz 2005). 15 Material Iron metal Steel Steel kg 1. 95) Other K-factors can be provided as optional withoutThe strain hardening exponent (also called the strain hardening index), usually denoted , a constant often used in calculations relating to stress–strain behavior in work hardening. We bend lots of stainless, which in terms of hardness, is. parts in 304 stainless steel and aluminized steel, I have my k-factor set to 0. 3-0. It is a function of the materials' frictional characteristics, which are based on surface finish, coatings and so on. 1 mm can be made in polypropylene PP, aluminum or stainless steel. itic stainless steel that is molybdenum alloyed for enhanced corrosion resistance in chloride environments. The K-Factor is a property of the material being bent. 1 lists ferrous and nonferrous metalRelated Resources: materials Specific Heat Capacity of Metals Table Chart. R. 3 in. Stainless Steel SUS304 – SUS304 is one of the most widely used stainless steels and contains nickel, which provides better corrosion and heat resistance than chromium. Stainless Steel: ASME 150#-2500# Flanges-100°C upto 232°C: Degreased / Cleaned: N/A: Red, Blue, Green: ASTM A453 Grade 660 Class B: 232°C upto 325°C: Ceramic Xylar-2: 25µm ±5µm:. while stainless steel plates can. 45 The K-factor also increases with harder materials such as steel and stainless steel but never exceeds the 0. The k-factor value signifies how far the neutral axis shifts during bending. Determining the proper torque for a fastener is the biggest problem in fastener installation. It appears that stainless steel bolts can be applied in aluminium slip resistant connections, but a larger partial safety factor than standards currently prescribe is required for the slip. The best single-volume reference on the metallurgy, selection, processing, performance, and evaluation of stainless steels, incorporating essential information culled from across the ASM Handbook series. Subcategory: Ferrous Metal; Metal; Stainless Steel; T 300 Series Stainless Steel Key Words: UNS S31600, SS316, 316SS, AISI 316, DIN 1. Calculation of spring force at a given length is travel s * R. It has units of m 2 /s. Comparative Pipe Roughness Values: Material: Manning's Coefficient n: Hazen-Williams C: Darcy-Weisbach Roughness Height k (mm) k (0. This Table is applicable to Never-Seize paste and Fel-Pro lubricant, K=0. The heat transfer convection coefficient for air is 50 W/m 2 K . 8 mm mild steel sheet with a 0. 1. 2 P a. Grade 301 Temper ASTM. Keep in mind that there will be a reduction rating when sensing stainless steel. The specific heat is the amount of heat energy per unit mass required to raise the temperature by one degree Celsius. Land Width: 0. k = 0. Product code: ISBN: 978-0-87170-503-7. relieved thermally or mechanically. Table 8: Sample Torque Calculation with varying K Factor. 20 Ecoguard K = 0. Minor or dynamic pressure loss in pipe or tube system components can be expressed as. Use K-Factor Calculator to calculate k factor values. 2, θ / σ 0. Therefore, the K factor remains constant. During sheet metal part bending, the inside bending surface is compressed, whereas the outer surface is stretched. The bend test is obtained around a diameter of the bend factor multiplied by the steel thickness. Below is a discussion of several 316 stainless steel characteristics:Find the linear expansion coefficient for steel: 12. The CTE employs reciprocal temperature units (K-1, °F-1, °C-1, etc. The above Table is applicable only for ASTM A320 Grade B8, Class 2 and A193 Grade B8, Class 2 Stud Bolts. It offers good corrosion protection, under high loads, over a wide temperature range. (7-8 mm) thick material Austenitic Material (T304) 0. Loctite 242 is a lubricant. [1] It is a measure of the rate of heat transfer inside a material. There is a direct relationship between sheet metal bend allowance and the K-factor. The Math /. Stainless steel bolts are formed when the raw materials of nickel, iron ore, chromium, silicon, molybdenum, and others, are melted together. Specific Heat Capacity of Metals Table Chart . 6% max), chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium, etc. K)/W] in SI units or [ (ft 2 ·°F·hr)/Btu] in imperial units. 5% chromium and no more than 1. Features a 3/4 inch NPT (20 mm BSPT) thread size and 8. A typical uncertainty in the roughness values can be assumed to be in the range ± − 30 -50 %. First, we choose the option to use a gauge table. Manufacturer: Viking. 0 (115) Download Bulletin. Thread: 15mm (1/2") NPT, (BSPT optional) K-factor: 115 (8. 3 to SDR 26), PVC (Schedule 40, 80, and CL100 to CL315), Stainless Steel (Schedule 5s, 10s, 40s), Steel (Schedule 40,80,160) and more. ASME. 0. Material. At this level, chromium reacts5. Usually, we secure the screws with Loctite 242. Thermal Conductivity - Online Converter Convert between thermal conductivity units. Our bend radius rule of thumb is the minimum radius = material thickness. 5 in, wall thickness 0. It determines how much the material will stretch when it is bent. 33 in practical use and at my shop they use as small as 0. With this equation, if you know K, F and D, you can multiply them to get the torque needed to tighten the bolt so that it has the right amount of tension. 1. Here we need to discuss: Non-Lubricated Bolts (a. 0015 10 -3 (m) , hydraulic diameter d h = 0. So if the thickness of the sheet was a distance of T = 1 mm and the location of the neutral axis was a distance of t = 0. It enters a region where da/dN is linearly dependent upon log ΔK.