Technical Q&A · 2026-06-07
38 degrees and 45 degrees EVA Foam Sheet how to choose?
38 degrees and 45 degrees can be used as common hardness communication directions, but they should not be judged independently of density, thickness, application, and subsequent processing methods.
EVA sheet hardness mean?
Hardness is used to describe the feel, rebound, and support direction of EVA Foam Sheet. In procurement communications, customers often mention 38 degrees or 45 degrees, but hardness is not the only indicator. Boards with the same hardness may feel different in actual use if their density, thickness, color, foaming state, or subsequent processing methods differ. Therefore, hardness is more suitable as a starting point for communication rather than the sole condition for determining whether a product is suitable.
For customers who need to purchase in bulk, it is recommended to describe hardness together with usage. For example, whether the sheets are for shoe lining materials, packaging cushioning, bag linings, or sports mat applications, whether subsequent lamination, slitting, or die-cutting is required, and whether the desired feel is softer or more supportive, all of this information will affect the specification communication.
38 Degrees Common Communication Directions
38 degrees is generally understood as a commonly soft hardness direction, suitable for basic sheet material applications that have certain requirements for touch, fit, or cushioning. For example, some downstream processing directions for shoe materials, bag linings, or sports mat materials may use 38 degrees as an initial reference for communication. However, this does not mean that all 38-degree sheets are suitable for the same purposes, nor does it imply that there are fixed ready-made specifications.
If the customer wishes to choose the 38-degree direction, it is recommended to also provide thickness, density, size, color, quantity, and reference samples. Especially for customers who have requirements for subsequent lamination or die-cutting, it is best to specify the processing method and the part of use, in order to determine whether the material's feel and support are appropriate.
45 Degree Common Communication Directions
45 degrees is usually understood as the common hardness direction with stronger support, suitable for sheet materials that have higher requirements for firmness, support, or shape retention. Some applications such as packaging cushioning, industrial padding, shoe material support, or other uses that require stronger support will use 45 degrees as a reference for communication.
at 45 degrees, attention also needs to be paid to thickness and density. Thin sheets and thick sheets, even if the hardness direction is similar, may feel different in actual use. If the purchaser only provides the information '45 degrees,' the factory still needs to further confirm the purpose, size, color, quantity, and packaging method.
Why can't we just look at hardness
| Hardness Direction | Common Understanding | Factors that still need to be confirmed |
|---|---|---|
| 38 degrees | Slightly soft, with a more noticeable sense of fit | Density, thickness, usage, target feel, subsequent processing method |
| 45 degrees | Stronger support feeling, more noticeable firmness | Direction of force, dimensions, color, quantity, packaging method |
| Other hardness | Communicate According to Order Direction | samples, reference panels, budget, and application scenarios |
There is a correlation between hardness, density, and thickness. If the customer has samples or reference sheets, it is recommended to provide them together; if there are no samples, the requirements can also be described based on the desired feel, usage location, load-bearing conditions, and subsequent processing methods. This is more conducive to communication than providing just a single hardness number.
?
If the customer already has a target product, they can also provide additional information such as the usage environment, whether long-term pressure resistance is needed, whether it needs to bond with other materials, and whether roll or full board packaging is required. These details will not replace the hardness and density parameters, but they can help the factory understand the actual usage scenario more quickly and reduce repeated confirmations based solely on a single number.
- Purpose: footwear materials, packaging, bags, sports padding materials, industrial cushioning, or other directions.
- Specifications: thickness, density, dimensions, color, quantity, and packaging method.
- Reference: sample, desired tactile feel, subsequent processing method, or usage part.
- Series: If you are not sure about the A series or C series, you can first specify the budget and usage requirements.
The relationship between hardness, density, and thickness
When customers compare 38 degrees and 45 degrees, they often understand hardness as the 'soft or hard feel.' This understanding has some reference value, but it is not complete. Density affects the sense of solidity and support of the board, thickness affects actual stress and cushioning performance, and color and foam state may also affect the surface appearance of the board. For downstream processing customers, hardness, density, and thickness usually need to be considered together.
For example, for sheets that are similarly on the softer side, if the thickness is relatively thin, the actual support may be insufficient; likewise, for sheets with stronger support, if the density and intended use do not match, it may also affect subsequent laminating or die-cutting effects. Therefore, when factories receive an inquiry, they usually continue to confirm the density, thickness, dimensions, and intended use, rather than judging solely based on a hardness number.
Procurement/Inquiry Parameter List
| Parameter | Recommendation Explanation | Why does it affect hardness selection |
|---|---|---|
| Purpose | Shoe materials, packaging, bags, sports mat materials, etc. | determines a softer, supportive, or cushioning direction |
| Density | already has parameters, reference samples, or target feel | Impact on sense of fulfillment, support, and cost communication |
| Thickness | Single sheet thickness, whether multiple thicknesses are needed | affects actual force and user experience |
| Subsequent Processing | Customer subsequent slitting, laminating, die-cutting, or combination | affects the texture of the sheet and the choice of size |
How should customers describe their requirements when they are unsure about hardness
If the customer does not know whether to choose 38 degrees or 45 degrees, they can describe their needs based on the usage scenario. For example, 'hope for a softer feel, later to fit fabric,' 'for packaging cushioning, need to protect lighter products,' 'for support layer, hope it does not collapse easily,' 'already have samples but do not know the hardness parameters.' These descriptions can help the factory determine the preliminary direction.
For foreign trade customers, if there is no hardness expression in Chinese, sample photos, intended use, finished product structure diagrams, or target texture descriptions can also be provided. For domestic customers, if there are existing old panels, samples or measurements of thickness, dimensions, color, and use can be provided. Regardless of the method, the core is to clearly explain the actual usage requirements.
sample confirmation in hardness selection
Hardness numbers can help both parties establish an initial direction, but samples and actual usage better reflect the feel that customers need. For customers requiring fitting, die-cutting, or support, it is recommended not to judge softness or hardness based solely on text, but to provide reference sheets or explain the structure of the target product as much as possible. Sample confirmation can help customers compare the differences between 38 degrees, 45 degrees, or other hardness levels at actual thickness.
If an order involves multiple thicknesses or multiple colors, it is also recommended to confirm the hardness direction separately. Even if sheets of different thicknesses have similar hardness, the feel and support may differ, and communicating separately can reduce discrepancies after bulk purchases.
Frequently Asked Questions
38 degrees necessarily very soft?
Not necessarily. 38 degrees is usually communicated as leaning towards softness, but the actual feel will also be affected by density, thickness, and intended use. It is recommended to confirm in combination with a sample or the desired feel.
45 degrees necessarily very hard?
45 degrees generally provide stronger support, but this does not mean they are suitable for all situations. For different uses such as packaging, footwear materials, and industrial cushioning, the understanding of support and rebound will differ.
Can we discuss other hardness levels?
can be discussed according to order requirements. It is recommended to provide the intended use, samples, thickness, density, dimensions, color, and quantity, so that both parties can confirm feasible specification directions.
has no hardness parameter, can a price inquiry be made?
is fine. The customer can first explain the purpose, desired feel, subsequent processing method, and expected quantity, and then the factory will assist in discussing possible suitable specification directions.
If you need to discuss the EVA Foam Slab specifications, you can provide the purpose, thickness, hardness, density, size, color, and estimated quantity.